{"gene":"ARAP3","run_date":"2026-06-09T22:02:44","timeline":{"discoveries":[{"year":2002,"finding":"ARAP3 is a specific PtdIns(3,4,5)P3/PtdIns(3,4)P2-stimulated Arf6 GAP both in vitro and in vivo, and both its Arf GAP and Rho GAP domains cooperate in mediating PI3K-dependent rearrangements in cell cytoskeleton and cell shape. ARAP3 was identified by selective capture on phosphoinositide affinity matrices from leukocyte extracts and has five PH domains.","method":"Phosphoinositide affinity matrix capture, mass spectrometry identification, in vitro and in vivo GAP activity assays","journal":"Molecular cell","confidence":"High","confidence_rationale":"Tier 1 / Strong — in vitro biochemical reconstitution of GAP activity plus in vivo validation, replicated in subsequent studies","pmids":["11804589"],"is_preprint":false},{"year":2004,"finding":"ARAP3 functions as a RhoA-preferring Rho GAP (not other Rho family members) and is directly activated in vitro by GTP-bound Rap proteins binding to its Ras-binding domain (RBD). This activation is GTP-dependent and specific for Rap versus other Ras family members. PI3K activity was required for Rap-mediated activation in a cellular context, suggesting PtdIns(3,4,5)P3-dependent membrane translocation is required for subsequent Rap activation.","method":"In vitro GAP activity assays, direct binding assays with Rap proteins, cellular PI3K inhibition experiments","journal":"Current biology : CB","confidence":"High","confidence_rationale":"Tier 1 / Strong — in vitro biochemical reconstitution with mutagenesis context, replicated in subsequent studies","pmids":["15296756"],"is_preprint":false},{"year":2004,"finding":"ARAP3 is tyrosine phosphorylated by Src-family kinases (SFKs) upon adhesion to fibronectin, growth factor stimulation, and co-expression with SFKs. Adhesion-induced phosphorylation was suppressed by SFK and PI3K inhibitors. ARAP3 inhibits cell spreading in a RhoGAP-dependent manner, reducing active RhoA and Rac1 levels. Mutation of phosphorylation sites Y1399 and Y1404 enhanced ARAP3 activities, indicating negative regulation by phosphorylation on these tyrosines.","method":"Co-expression with SFKs, pharmacological inhibitors, dominant-negative mutants, inducible expression, RhoA/Rac1 activity assays, site-directed mutagenesis","journal":"Journal of cell science","confidence":"High","confidence_rationale":"Tier 2 / Moderate — multiple orthogonal methods (pharmacological, genetic, biochemical) in a single study with specific mutagenesis","pmids":["15546919"],"is_preprint":false},{"year":2004,"finding":"ARAP3 deficiency impairs entry of anthrax protective antigen (PA) and its bound toxigenic moieties into human and mouse cells, identifying ARAP3 as a host factor essential for cellular internalization of anthrax toxin, consistent with its role in membrane vesicle trafficking.","method":"EST-based genome-wide gene inactivation screen, antisense expression, cell survival assay after PA-dependent toxin treatment","journal":"Proceedings of the National Academy of Sciences of the United States of America","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — genome-wide phenotypic screen with follow-up antisense validation in human and mouse cells, single lab","pmids":["15569923"],"is_preprint":false},{"year":2006,"finding":"ARAP3 is essential for lamellipodia formation after growth factor stimulation in endothelial cells. ARAP3-deficient cells show increased RhoA and Arf6 activities, are more rounded, display fine stress fibres, and cannot produce lamellipodia. Rac was activated but mislocalized in ARAP3-deficient cells, likely due to increased Arf6 activity. ARAP3 recruitment to sites of elevated PtdIns(3,4,5)P3 allows localized RhoA inactivation and Arf6 cycling.","method":"RNAi knockdown in endothelial cells, RhoA/Arf6/Rac activity assays, confocal microscopy of cell morphology and actin dynamics","journal":"Journal of cell science","confidence":"High","confidence_rationale":"Tier 2 / Strong — RNAi loss-of-function with defined cellular phenotypes and GTPase activity measurements, replicated concept across multiple papers","pmids":["16418224"],"is_preprint":false},{"year":2006,"finding":"ARAP3's domain structure includes five PH domains, an Arf GAP domain, three ankyrin repeats, a Rho GAP domain, and a Ras association domain. It is a PtdIns(3,4,5)P3-dependent GAP for Arf6 in vitro and in vivo, and a Rap-GTP-activated RhoA GAP in vitro requiring direct interaction between ARAP3 and Rap-GTP; in vivo, PtdIns(3,4,5)P3 is required to enable RhoA GAP activation by Rap-GTP.","method":"Protein purification, in vitro GAP activity assays, overexpression phenotype analysis in PAE cells","journal":"Methods in enzymology","confidence":"High","confidence_rationale":"Tier 1 / Strong — purified protein reconstitution with in vitro GAP assays, confirmed by multiple earlier and subsequent studies","pmids":["16472652"],"is_preprint":false},{"year":2007,"finding":"ARAP3 interacts with the PI(3,4,5)P3 phosphatase SHIP2 through a SAM domain-mediated heterodimeric interaction. The SAM domain of ARAP3 and the SAM domain of SHIP2 show specificity for heterodimeric interaction in vitro. This interaction was confirmed with endogenous proteins.","method":"Yeast two-hybrid screen, endogenous co-immunoprecipitation, in vitro SAM domain binding assay","journal":"Cellular signalling","confidence":"High","confidence_rationale":"Tier 2 / Moderate — reciprocal endogenous Co-IP plus in vitro domain-specific binding, multiple methods in one study","pmids":["17314030"],"is_preprint":false},{"year":2009,"finding":"ARAP3 binds PtdIns(3,4,5)P3 through an unusual mechanism requiring the N-terminal tandem PH domains plus an N-terminal linker region. No single PH domain is sufficient for binding. The N-terminal SAM domain further contributes to substantial binding. Site-directed mutagenesis of either N-terminal PH domain greatly reduces PtdIns(3,4,5)P3 binding, and deletion of any single PH domain abolishes binding.","method":"PtdIns(3,4,5)P3 binding assays with truncation and point mutants, site-directed mutagenesis","journal":"Cellular signalling","confidence":"High","confidence_rationale":"Tier 1 / Moderate — systematic mutagenesis and domain deletion analysis with direct lipid binding assays, single lab","pmids":["19786092"],"is_preprint":false},{"year":2009,"finding":"The NMR solution structure of Arap3-SAM was determined, and heterodimeric interaction with Ship2-SAM was characterized. Arap3-SAM associates with Ship2-SAM using a binding mode common to other SAM domain pairs, identical to Ship2-SAM/EphA2-SAM interaction. Key structural features mediating SAM-SAM interactions were identified.","method":"NMR solution structure determination, ITC, mutagenesis, molecular modeling","journal":"BMC structural biology","confidence":"High","confidence_rationale":"Tier 1 / Moderate — NMR structure determination plus ITC thermodynamic validation and mutagenesis in one study","pmids":["19765305"],"is_preprint":false},{"year":2010,"finding":"ARAP3 deletion in mice causes embryonic death in mid-gestation due to an endothelial cell-autonomous defect in sprouting angiogenesis. Knock-in mice with an ARAP3 point mutant that cannot be activated by PtdIns(3,4,5)P3 have similar angiogenesis defects, establishing that PI3Kα signals through ARAP3 (via PtdIns(3,4,5)P3 activation) to control RhoA and Arf6 during angiogenesis.","method":"Arap3 knockout mouse, PtdIns(3,4,5)P3-binding point mutant knock-in mouse, ex vivo explant assays, genetic epistasis","journal":"Science signaling","confidence":"High","confidence_rationale":"Tier 2 / Strong — two independent mouse genetic models (KO and point-mutant KI) with ex vivo phenotype confirmation, establishing pathway position","pmids":["20978237"],"is_preprint":false},{"year":2010,"finding":"ARAP3 inactivates RhoA downstream of Rap1 during neurite outgrowth in PC12 cells in response to bFGF. Dominant-negative ARAP3 and dominant-negative Rap1 both reduced neurite formation, placing ARAP3 as a Rap1 effector that inactivates RhoA to enable neurite outgrowth.","method":"Dominant-negative ARAP3 expression in PC12 cells, GTP-RhoA activity assays, neurite outgrowth quantification","journal":"Journal of cellular physiology","confidence":"Medium","confidence_rationale":"Tier 3 / Moderate — dominant-negative approach with phenotypic readout, replicated with NGF in a companion paper","pmids":["20578246"],"is_preprint":false},{"year":2010,"finding":"In PC12 cells responding to NGF, ARAP3 acts downstream of Rap1 to inactivate RhoA and enable neurite outgrowth. Dominant-negative ARAP3 prevented RhoA inactivation and abolished neurite formation. RhoA was co-immunoprecipitated with Rap1, and NGF activated Rap1.","method":"Dominant-negative expression, GTP-RhoA activity assays, co-immunoprecipitation of RhoA and Rap1, neurite outgrowth quantification","journal":"Experimental & molecular medicine","confidence":"Medium","confidence_rationale":"Tier 3 / Moderate — dominant-negative approach with Co-IP and activity assays, replicated the bFGF finding in the same cellular model with NGF","pmids":["20200473"],"is_preprint":false},{"year":2010,"finding":"ARAP3 overexpression in scirrhous gastric carcinoma cells inhibits peritoneal dissemination by regulating cell attachment to ECM and invasion. These effects required a functional Rho-GAP domain and the C-terminal tyrosine residues (Y1399/Y1404) phosphorylated by Src, but were suppressed by mutations in either the RhoGAP domain or these tyrosines.","method":"Overexpression in cancer cell lines, peritoneal dissemination assay, cell adhesion and invasion assays, RhoGAP domain mutants and tyrosine phosphorylation site mutants","journal":"Oncogene","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — domain mutagenesis with defined cellular phenotypes, single lab with multiple mutant analyses","pmids":["21076469"],"is_preprint":false},{"year":2011,"finding":"ARAP3 functions downstream of Rap in neutrophils to modulate β2 integrin affinity and avidity. ARAP3-deficient neutrophils are preactivated, show increased β2 integrin inside-out signaling, hyperresponsive adhesion-dependent functions (ROS formation, adhesion, spreading, granule release), and defective integrin-dependent chemotaxis. ARAP3 guards neutrophils in their quiescent state.","method":"Arap3 conditional knockout mouse neutrophils, β2 integrin activation assays, flow assays, intravital microscopy, in vitro chemotaxis","journal":"Blood","confidence":"High","confidence_rationale":"Tier 2 / Strong — conditional KO mouse with multiple orthogonal functional readouts both in vitro and in vivo","pmids":["21490342"],"is_preprint":false},{"year":2012,"finding":"PI3K regulates β2 integrin activity in neutrophils specifically through its effector ARAP3: neutrophils from ARAP3 PH domain point mutant knock-in mice (R302,303A, uncoupled from PI3K activation) show increased β2 integrin inside-out signaling and disturbed adhesion-dependent responses, with reduced neutrophil recruitment in vivo. Neutrophil chemotaxis was also affected.","method":"ARAP3 PH domain point mutant knock-in mouse, β2 integrin activation assays, in vitro chemotaxis, in vivo peritonitis and arthritis models, bone marrow chimeras","journal":"Journal of immunology","confidence":"High","confidence_rationale":"Tier 2 / Strong — knock-in mouse with a specific point mutation decoupling PI3K input, multiple in vitro and in vivo assays, establishes pathway position","pmids":["23180820"],"is_preprint":false},{"year":2012,"finding":"Arap3-SAM interacts with the first SAM domain of Odin (Odin-Sam1) with low micromolar affinity. NMR, SPR, ITC, and molecular docking revealed a heterotypic SAM-SAM binding topology common to other SAM domain complexes, identifying structural determinants for the interaction.","method":"NMR spectroscopy, SPR, ITC, molecular docking","journal":"Chembiochem","confidence":"Medium","confidence_rationale":"Tier 1 / Moderate — multiple biophysical methods (NMR, SPR, ITC) from a single lab characterizing a novel interaction","pmids":["23239578"],"is_preprint":false},{"year":2012,"finding":"Vav2 SH2 domain interacts directly with phosphorylated Y1403 and Y1408 (corresponding to the Src-phosphorylated tyrosines) within the C-terminal region of Arap3, with dissociation constants of ~0.27 and ~1.40 μM respectively. The solution structures of Vav2 SH2 domain free and in complex with pY1408 peptide were determined, revealing the structural basis for this recognition.","method":"ITC, NMR chemical shift perturbation, NMR solution structure determination, Co-IP in vivo","journal":"Journal of structural biology","confidence":"High","confidence_rationale":"Tier 1 / Moderate — NMR structure plus ITC quantification and in vivo Co-IP validation in one study","pmids":["22750419"],"is_preprint":false},{"year":2013,"finding":"ARAP3 is necessary for lymphatic vascular development in mice and zebrafish and acts as a mediator of the cellular response to Vegfc signaling in lymphatic endothelial cells. ARAP3 is downregulated in HLT mouse aberrant dermal lymphatic vessels, positioning it downstream of Vegfc in lymphangiogenesis.","method":"Mouse model gene expression profiling, zebrafish functional analysis, in vitro Vegfc signaling assays, in vivo lymphatic vessel analysis","journal":"Human molecular genetics","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — functional analysis in two model organisms with in vitro pathway placement, single lab","pmids":["24163130"],"is_preprint":false},{"year":2016,"finding":"Crystal structure of RhoA in complex with the RhoGAP domain of ARAP3 was solved, revealing the molecular interface. In vitro GTPase activity assays and ITC experiments identified crucial residues affecting RhoGAP catalytic activity and substrate specificity, explaining why ARAP3 preferentially activates RhoA over Rac1 and Cdc42.","method":"X-ray crystallography, in vitro GTPase activity assays, ITC, mutagenesis","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1 / Strong — crystal structure plus biochemical reconstitution with mutagenesis and calorimetry in one study","pmids":["27311713"],"is_preprint":false},{"year":2023,"finding":"The first PH domain of Arap3 (PH1) is sufficient to interact with PI(3,4,5)P3 (and with lower affinity PI(4,5)P2). The crystal structure of Arap3-PH1 in apo form and in complex with diC4-PI(3,4,5)P3 was determined, revealing the structural basis for specific phosphoinositide recognition. PI(3,4,5)P3-binding by PH1 is essential for ARAP3's ability to inhibit breast cancer cell invasion.","method":"Liposome pull-down, SPR, NMR, X-ray crystallography of apo and PI(3,4,5)P3-bound PH1, cell invasion assays with PH1 mutants","journal":"International journal of molecular sciences","confidence":"High","confidence_rationale":"Tier 1 / Moderate — crystal structure plus multiple orthogonal biophysical methods and functional cell assay validating the structural finding","pmids":["36674645"],"is_preprint":false},{"year":2024,"finding":"ARAP3 protects against formylated peptide-induced microvascular permeability through both endothelial cells and neutrophils. In vitro, Arap3-/- endothelial monolayers show enhanced permeability due to upregulated FPR1 and enhanced VE-cadherin internalisation. In vivo, loss of ARAP3 leads to excessive microvascular leakage and neutrophil extracellular trap (NET) formation; pharmacological inhibition of NET formation abrogated the excessive leakage.","method":"Arap3 knockout mouse, endothelial monolayer permeability assays, adoptive transfer experiments, pharmacological NET inhibition, bronchoalveolar lavage analysis, influenza infection model","journal":"The Journal of pathology","confidence":"High","confidence_rationale":"Tier 2 / Moderate — multiple in vitro and in vivo approaches with mechanistic dissection of cell types and molecular events, single lab","pmids":["38734878"],"is_preprint":false}],"current_model":"ARAP3 is a dual GTPase-activating protein for Arf6 and RhoA that functions as a PI3K effector: PtdIns(3,4,5)P3 (generated by PI3Kα) recruits ARAP3 to the plasma membrane via its tandem N-terminal PH domains (structurally characterized) and catalytically activates its Arf6 GAP activity, while its RhoA GAP activity is further activated by direct binding of GTP-Rap to its RBD domain; Src-family kinases phosphorylate C-terminal tyrosines (Y1399/Y1404) to negatively regulate ARAP3 and recruit Vav2 via its SH2 domain; the SAM domain mediates heterodimeric interactions with SHIP2 and Odin; downstream, ARAP3 controls cell shape, lamellipodia formation, β2 integrin activity in neutrophils, sprouting angiogenesis, lymphangiogenesis, and vascular permeability by coordinating localized inactivation of RhoA and cycling of Arf6 at sites of PI3K signaling."},"narrative":{"mechanistic_narrative":"ARAP3 is a phosphoinositide-regulated dual GTPase-activating protein that converts localized PI3K signaling into coordinated control of Arf6 and RhoA, thereby shaping the actin cytoskeleton, cell adhesion, and vascular morphogenesis [PMID:11804589, PMID:16472652]. It is a PtdIns(3,4,5)P3/PtdIns(3,4)P2-stimulated Arf6 GAP and a RhoA-preferring Rho GAP whose Rho GAP activity is switched on by direct binding of GTP-loaded Rap to its Ras-binding domain, with PtdIns(3,4,5)P3-dependent membrane recruitment required to license this Rap-driven activation in cells [PMID:11804589, PMID:15296756, PMID:16472652]; the structural basis for its RhoA preference over Rac1 and Cdc42 was resolved in a RhoA-RhoGAP domain co-crystal [PMID:27311713]. Membrane recruitment depends on an unusual lipid-binding mode in which tandem N-terminal PH domains, an N-terminal linker, and the SAM domain cooperate, with the first PH domain alone sufficient for specific PtdIns(3,4,5)P3 recognition [PMID:19786092, PMID:36674645]. ARAP3 is negatively regulated by Src-family kinase phosphorylation of C-terminal tyrosines (Y1399/Y1404), which creates a docking site bound by the Vav2 SH2 domain [PMID:15546919, PMID:22750419], while its SAM domain mediates heterodimeric interactions with the PtdIns(3,4,5)P3 phosphatase SHIP2 and with Odin [PMID:17314030, PMID:19765305, PMID:23239578]. Through these activities ARAP3 enables lamellipodia formation, neurite outgrowth downstream of Rap1, and restrains cell spreading, adhesion, and invasion [PMID:15546919, PMID:16418224, PMID:20578246, PMID:21076469]. In vivo it acts as the endothelial PI3Kα effector required for sprouting angiogenesis and lymphangiogenesis, guards neutrophils in a quiescent state by limiting β2 integrin inside-out signaling, and protects against microvascular permeability and NET formation [PMID:20978237, PMID:21490342, PMID:23180820, PMID:38734878].","teleology":[{"year":2002,"claim":"Established ARAP3 as a phosphoinositide-responsive enzyme by showing it is a PtdIns(3,4,5)P3-stimulated Arf6 GAP whose Arf and Rho GAP domains together drive PI3K-dependent cytoskeletal and cell-shape changes, linking lipid signaling to GTPase control.","evidence":"Phosphoinositide affinity capture and mass spectrometry from leukocyte extracts with in vitro and in vivo GAP assays","pmids":["11804589"],"confidence":"High","gaps":["Did not define the structural basis for lipid binding","Rho GAP substrate specificity not yet resolved"]},{"year":2004,"claim":"Defined the Rho GAP arm as RhoA-specific and showed it is allosterically activated by direct binding of GTP-Rap to the RBD, with PI3K required in cells, establishing ARAP3 as a coincidence detector of Rap-GTP and PtdIns(3,4,5)P3.","evidence":"In vitro GAP and direct Rap-binding assays plus cellular PI3K inhibition","pmids":["15296756"],"confidence":"High","gaps":["Structural interface of Rap-RBD binding not determined","How PtdIns(3,4,5)P3 and Rap inputs are integrated mechanistically unresolved"]},{"year":2004,"claim":"Identified Src-family kinase phosphorylation of C-terminal tyrosines Y1399/Y1404 as a negative regulatory input, since mutating these sites enhanced ARAP3 activity and adhesion-dependent inhibition of spreading.","evidence":"SFK co-expression, pharmacological inhibitors, site-directed mutagenesis, RhoA/Rac1 activity assays","pmids":["15546919"],"confidence":"High","gaps":["Downstream effector of phosphorylated tyrosines not identified at this stage","In vivo relevance of phosphoregulation not tested"]},{"year":2004,"claim":"Implicated ARAP3 in membrane internalization by showing its loss impairs anthrax protective antigen entry, consistent with a vesicle-trafficking role.","evidence":"Genome-wide gene inactivation screen with antisense validation and toxin survival assay","pmids":["15569923"],"confidence":"Medium","gaps":["Mechanistic link between ARAP3 GAP activity and toxin uptake not established","Single-lab phenotypic screen without enzymatic dissection"]},{"year":2006,"claim":"Demonstrated the cellular consequence of coordinated GTPase control: ARAP3 is required for growth-factor-induced lamellipodia, with its loss raising RhoA and Arf6 activity and mislocalizing Rac.","evidence":"RNAi in endothelial cells with RhoA/Arf6/Rac activity assays and confocal morphology","pmids":["16418224"],"confidence":"High","gaps":["Did not separate Arf6 versus RhoA contributions to lamellipodia","Recruitment kinetics at PtdIns(3,4,5)P3 sites not measured"]},{"year":2007,"claim":"Revealed a protein-interaction layer by identifying a SAM-domain heterodimer between ARAP3 and the PtdIns(3,4,5)P3 phosphatase SHIP2, suggesting spatial coupling of lipid production and turnover.","evidence":"Yeast two-hybrid, endogenous reciprocal Co-IP, in vitro SAM binding","pmids":["17314030"],"confidence":"High","gaps":["Functional consequence of the ARAP3-SHIP2 complex for signaling not tested","Stoichiometry and cellular context of the interaction unknown"]},{"year":2009,"claim":"Defined the unusual membrane-targeting mechanism, showing PtdIns(3,4,5)P3 binding requires cooperation of tandem PH domains, an N-terminal linker, and the SAM domain rather than a single PH module.","evidence":"Lipid-binding assays with truncations and point mutants","pmids":["19786092"],"confidence":"High","gaps":["High-resolution structure of the bound state not yet available","Conflicts with later finding that PH1 alone suffices needed reconciling"]},{"year":2009,"claim":"Provided the structural basis for the SHIP2 interaction by solving the Arap3-SAM NMR structure and showing it uses a canonical SAM-SAM binding mode shared with EphA2.","evidence":"NMR solution structure, ITC, mutagenesis, modeling","pmids":["19765305"],"confidence":"High","gaps":["Did not establish in vivo signaling output of the SAM heterodimer","Competition among SAM partners not addressed"]},{"year":2010,"claim":"Positioned ARAP3 genetically as the PI3Kα effector for angiogenesis by showing both knockout and a PtdIns(3,4,5)P3-uncoupling knock-in mouse cause endothelial-autonomous sprouting defects and mid-gestation lethality.","evidence":"Arap3 knockout and lipid-binding point-mutant knock-in mice with ex vivo explants and genetic epistasis","pmids":["20978237"],"confidence":"High","gaps":["Relative in vivo contributions of Arf6 versus RhoA control not dissected","Downstream cytoskeletal effectors in sprouting not mapped"]},{"year":2010,"claim":"Extended the Rap1-effector role to neuronal differentiation, showing ARAP3 inactivates RhoA downstream of Rap1 to permit bFGF- and NGF-induced neurite outgrowth.","evidence":"Dominant-negative ARAP3 in PC12 cells with GTP-RhoA assays, Rap1-RhoA Co-IP, and neurite quantification","pmids":["20578246","20200473"],"confidence":"Medium","gaps":["Relied on dominant-negative rather than loss-of-function","Endogenous ARAP3 requirement in neurons not confirmed"]},{"year":2010,"claim":"Linked ARAP3 to suppression of cancer cell invasion, showing overexpression inhibits gastric carcinoma peritoneal dissemination in a manner dependent on both the Rho GAP domain and the Src-target tyrosines.","evidence":"Overexpression with domain and tyrosine mutants in dissemination, adhesion, and invasion assays","pmids":["21076469"],"confidence":"Medium","gaps":["Overexpression-based; endogenous tumor-suppressive role not tested","Connection to Arf6 cycling in invasion not examined"]},{"year":2011,"claim":"Defined a physiological immune role, showing ARAP3 acts downstream of Rap to keep neutrophils quiescent by restraining β2 integrin affinity and avidity.","evidence":"Conditional knockout neutrophils with integrin activation, flow, intravital, and chemotaxis assays","pmids":["21490342"],"confidence":"High","gaps":["Did not separate which GAP activity controls integrin signaling","Molecular link from ARAP3 to inside-out signaling unmapped"]},{"year":2012,"claim":"Pinned the neutrophil phenotype to PI3K input by showing a PH-domain point-mutant knock-in (R302,303A) uncoupled from PtdIns(3,4,5)P3 recapitulates β2 integrin dysregulation and impaired recruitment in vivo.","evidence":"PH-domain point-mutant knock-in mouse with integrin assays, chemotaxis, peritonitis/arthritis models, bone marrow chimeras","pmids":["23180820"],"confidence":"High","gaps":["Downstream GTPase events controlling integrin activation not resolved","Cell-intrinsic versus systemic effects only partly separated"]},{"year":2012,"claim":"Resolved the structural basis of phosphotyrosine readout, showing the Vav2 SH2 domain directly binds the Src-phosphorylated C-terminal tyrosines with micromolar affinity, identifying a recruited partner of inhibited ARAP3.","evidence":"ITC, NMR chemical shift perturbation, NMR structure of Vav2 SH2-pY1408 complex, in vivo Co-IP","pmids":["22750419"],"confidence":"High","gaps":["Functional consequence of Vav2 recruitment to ARAP3 not established","Whether recruitment alters ARAP3 GAP output unknown"]},{"year":2012,"claim":"Characterized a second SAM-domain partner, defining the heterotypic Arap3-SAM/Odin-Sam1 interface and binding topology.","evidence":"NMR, SPR, ITC, molecular docking","pmids":["23239578"],"confidence":"Medium","gaps":["Cellular and physiological role of the ARAP3-Odin complex untested","How Odin and SHIP2 compete for the same SAM domain unresolved"]},{"year":2013,"claim":"Broadened the vascular role to lymphatics, placing ARAP3 downstream of Vegfc as a mediator required for lymphangiogenesis in mouse and zebrafish.","evidence":"Mouse expression profiling, zebrafish functional analysis, in vitro Vegfc assays, in vivo lymphatic analysis","pmids":["24163130"],"confidence":"Medium","gaps":["GTPase targets in lymphatic endothelium not dissected","Direct Vegfc-to-ARAP3 signaling link not biochemically defined"]},{"year":2016,"claim":"Explained RhoA substrate preference at atomic resolution by solving the RhoA-RhoGAP domain complex and identifying residues governing catalysis and specificity over Rac1 and Cdc42.","evidence":"X-ray crystallography, GTPase assays, ITC, mutagenesis","pmids":["27311713"],"confidence":"High","gaps":["Did not capture the Rap-activated conformation","Full-length autoregulated state not structurally resolved"]},{"year":2023,"claim":"Refined the lipid-recognition model by showing PH1 alone is sufficient for specific PtdIns(3,4,5)P3 binding, solving apo and lipid-bound structures and tying PH1 binding to inhibition of breast cancer invasion.","evidence":"Liposome pull-down, SPR, NMR, crystallography of PH1, cell invasion assays with PH1 mutants","pmids":["36674645"],"confidence":"High","gaps":["Relationship between PH1-only binding and earlier multi-domain requirement not fully reconciled","Structure of all five PH domains together unsolved"]},{"year":2024,"claim":"Established a barrier-protective function, showing ARAP3 limits microvascular permeability through both endothelial cells (restraining FPR1 and VE-cadherin internalization) and neutrophils (limiting NET formation).","evidence":"Arap3 knockout mouse, endothelial permeability assays, adoptive transfer, NET inhibition, influenza model","pmids":["38734878"],"confidence":"High","gaps":["Direct GAP-substrate events controlling VE-cadherin trafficking not pinpointed","Mechanism connecting ARAP3 to FPR1 expression unknown"]},{"year":null,"claim":"How the multiple inputs (PtdIns(3,4,5)P3 binding, Rap-GTP, Src phosphorylation, SAM partners) are integrated to set the timing and magnitude of Arf6 versus RhoA inactivation at a given membrane site remains unresolved.","evidence":"","pmids":[],"confidence":"High","gaps":["No full-length autoinhibited structure","Functional output of SHIP2, Odin, and Vav2 binding not mechanistically integrated","Quantitative model of dual-GAP coordination in vivo lacking"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0140096","term_label":"catalytic activity, acting on a protein","supporting_discovery_ids":[0,1,5,18]},{"term_id":"GO:0098772","term_label":"molecular function regulator activity","supporting_discovery_ids":[0,1,5,18]},{"term_id":"GO:0008289","term_label":"lipid binding","supporting_discovery_ids":[0,7,19]},{"term_id":"GO:0060089","term_label":"molecular transducer activity","supporting_discovery_ids":[1,10,14]}],"localization":[{"term_id":"GO:0005886","term_label":"plasma membrane","supporting_discovery_ids":[0,4,9]}],"pathway":[{"term_id":"R-HSA-162582","term_label":"Signal Transduction","supporting_discovery_ids":[0,1,9]},{"term_id":"R-HSA-168256","term_label":"Immune System","supporting_discovery_ids":[13,14,20]},{"term_id":"R-HSA-1266738","term_label":"Developmental Biology","supporting_discovery_ids":[9,17]}],"complexes":[],"partners":["RHOA","ARF6","RAP1","SHIP2","INPPL1","VAV2","ANKS1A","SRC"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"Q8WWN8","full_name":"Arf-GAP with Rho-GAP domain, ANK repeat and PH domain-containing protein 3","aliases":["Centaurin-delta-3","Cnt-d3"],"length_aa":1544,"mass_kda":169.8,"function":"Phosphatidylinositol 3,4,5-trisphosphate-dependent GTPase-activating protein that modulates actin cytoskeleton remodeling by regulating ARF and RHO family members. Is activated by phosphatidylinositol 3,4,5-trisphosphate (PtdIns(3,4,5)P3) binding. Can be activated by phosphatidylinositol 3,4-bisphosphate (PtdIns(3,4,5)P2) binding, albeit with lower efficiency. Acts on ARF6, RAC1, RHOA and CDC42. Plays a role in the internalization of anthrax toxin","subcellular_location":"Cytoplasm; Cytoplasm, cytoskeleton; Cell membrane; Cell projection, lamellipodium; Cell projection, ruffle","url":"https://www.uniprot.org/uniprotkb/Q8WWN8/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/ARAP3","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/ARAP3","total_profiled":1310},"omim":[{"mim_id":"619948","title":"INTERACTION PROTEIN FOR CYTOHESIN EXCHANGE FACTORS 1; IPCEF1","url":"https://www.omim.org/entry/619948"},{"mim_id":"606647","title":"ARF-GAP, RHO-GAP, ANKYRIN REPEAT, AND PLECKSTRIN HOMOLOGY DOMAINS-CONTAINING PROTEIN 3; ARAP3","url":"https://www.omim.org/entry/606647"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"","locations":[],"tissue_specificity":"Low tissue specificity","tissue_distribution":"Detected in all","driving_tissues":[],"url":"https://www.proteinatlas.org/search/ARAP3"},"hgnc":{"alias_symbol":["FLJ21065","DRAG1"],"prev_symbol":["CENTD3"]},"alphafold":{"accession":"Q8WWN8","domains":[{"cath_id":"1.10.150.50","chopping":"10-65","consensus_level":"high","plddt":85.5121,"start":10,"end":65},{"cath_id":"2.30.29.30","chopping":"291-385_393-482","consensus_level":"medium","plddt":85.734,"start":291,"end":482},{"cath_id":"1.10.220.150","chopping":"498-638","consensus_level":"high","plddt":88.6792,"start":498,"end":638},{"cath_id":"1.10.555.10","chopping":"921-1108","consensus_level":"high","plddt":91.4004,"start":921,"end":1108},{"cath_id":"3.10.20.90","chopping":"1115-1221","consensus_level":"medium","plddt":75.2153,"start":1115,"end":1221},{"cath_id":"2.30.29.30","chopping":"1224-1328","consensus_level":"medium","plddt":82.5105,"start":1224,"end":1328}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q8WWN8","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q8WWN8-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q8WWN8-F1-predicted_aligned_error_v6.png","plddt_mean":67.31},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=ARAP3","jax_strain_url":"https://www.jax.org/strain/search?query=ARAP3"},"sequence":{"accession":"Q8WWN8","fasta_url":"https://rest.uniprot.org/uniprotkb/Q8WWN8.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q8WWN8/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q8WWN8"}},"corpus_meta":[{"pmid":"11804589","id":"PMC_11804589","title":"Identification of ARAP3, a novel PI3K effector regulating both Arf and Rho GTPases, by selective capture on phosphoinositide affinity matrices.","date":"2002","source":"Molecular cell","url":"https://pubmed.ncbi.nlm.nih.gov/11804589","citation_count":245,"is_preprint":false},{"pmid":"15296756","id":"PMC_15296756","title":"ARAP3 is a PI3K- and rap-regulated GAP for RhoA.","date":"2004","source":"Current biology : CB","url":"https://pubmed.ncbi.nlm.nih.gov/15296756","citation_count":104,"is_preprint":false},{"pmid":"15546919","id":"PMC_15546919","title":"ARAP3 is transiently tyrosine phosphorylated in cells attaching to fibronectin and inhibits cell spreading in a RhoGAP-dependent manner.","date":"2004","source":"Journal of cell science","url":"https://pubmed.ncbi.nlm.nih.gov/15546919","citation_count":51,"is_preprint":false},{"pmid":"17314030","id":"PMC_17314030","title":"The PI3K effector Arap3 interacts with the PI(3,4,5)P3 phosphatase SHIP2 in a SAM domain-dependent 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signaling","url":"https://pubmed.ncbi.nlm.nih.gov/20978237","citation_count":39,"is_preprint":false},{"pmid":"20534671","id":"PMC_20534671","title":"The RGM protein DRAG-1 positively regulates a BMP-like signaling pathway in Caenorhabditis elegans.","date":"2010","source":"Development (Cambridge, England)","url":"https://pubmed.ncbi.nlm.nih.gov/20534671","citation_count":38,"is_preprint":false},{"pmid":"20578246","id":"PMC_20578246","title":"Neurite outgrowth from PC12 cells by basic fibroblast growth factor (bFGF) is mediated by RhoA inactivation through p190RhoGAP and ARAP3.","date":"2010","source":"Journal of cellular physiology","url":"https://pubmed.ncbi.nlm.nih.gov/20578246","citation_count":35,"is_preprint":false},{"pmid":"15569923","id":"PMC_15569923","title":"EST-based genome-wide gene inactivation identifies ARAP3 as a host protein affecting cellular susceptibility to anthrax toxin.","date":"2004","source":"Proceedings of the National Academy of Sciences of the United States of America","url":"https://pubmed.ncbi.nlm.nih.gov/15569923","citation_count":34,"is_preprint":false},{"pmid":"20200473","id":"PMC_20200473","title":"p190RhoGAP and Rap-dependent RhoGAP (ARAP3) inactivate RhoA in response to nerve growth factor leading to neurite outgrowth from PC12 cells.","date":"2010","source":"Experimental & molecular medicine","url":"https://pubmed.ncbi.nlm.nih.gov/20200473","citation_count":32,"is_preprint":false},{"pmid":"24163130","id":"PMC_24163130","title":"Arap3 is dysregulated in a mouse model of hypotrichosis-lymphedema-telangiectasia and regulates lymphatic vascular development.","date":"2013","source":"Human molecular genetics","url":"https://pubmed.ncbi.nlm.nih.gov/24163130","citation_count":29,"is_preprint":false},{"pmid":"19765305","id":"PMC_19765305","title":"The Sam domain of the lipid phosphatase Ship2 adopts a common model to interact with Arap3-Sam and EphA2-Sam.","date":"2009","source":"BMC structural biology","url":"https://pubmed.ncbi.nlm.nih.gov/19765305","citation_count":29,"is_preprint":false},{"pmid":"24004951","id":"PMC_24004951","title":"The neogenin/DCC homolog UNC-40 promotes BMP signaling via the RGM protein DRAG-1 in C. elegans.","date":"2013","source":"Development (Cambridge, England)","url":"https://pubmed.ncbi.nlm.nih.gov/24004951","citation_count":29,"is_preprint":false},{"pmid":"21076469","id":"PMC_21076469","title":"ARAP3 inhibits peritoneal dissemination of scirrhous gastric carcinoma cells by regulating cell adhesion and invasion.","date":"2010","source":"Oncogene","url":"https://pubmed.ncbi.nlm.nih.gov/21076469","citation_count":25,"is_preprint":false},{"pmid":"23180820","id":"PMC_23180820","title":"Phosphoinositide 3-OH kinase regulates integrin-dependent processes in neutrophils by signaling through its effector ARAP3.","date":"2012","source":"Journal of immunology (Baltimore, Md. : 1950)","url":"https://pubmed.ncbi.nlm.nih.gov/23180820","citation_count":18,"is_preprint":false},{"pmid":"23239578","id":"PMC_23239578","title":"Heterotypic Sam-Sam association between Odin-Sam1 and Arap3-Sam: binding affinity and structural insights.","date":"2012","source":"Chembiochem : a European journal of chemical biology","url":"https://pubmed.ncbi.nlm.nih.gov/23239578","citation_count":17,"is_preprint":false},{"pmid":"19786092","id":"PMC_19786092","title":"ARAP3 binding to phosphatidylinositol-(3,4,5)-trisphosphate depends on N-terminal tandem PH domains and adjacent sequences.","date":"2009","source":"Cellular signalling","url":"https://pubmed.ncbi.nlm.nih.gov/19786092","citation_count":14,"is_preprint":false},{"pmid":"27920554","id":"PMC_27920554","title":"Next-generation sequence detects ARAP3 as a novel oncogene in papillary thyroid carcinoma.","date":"2016","source":"OncoTargets and therapy","url":"https://pubmed.ncbi.nlm.nih.gov/27920554","citation_count":11,"is_preprint":false},{"pmid":"27311713","id":"PMC_27311713","title":"Structural Basis for the Specific Recognition of RhoA by the Dual GTPase-activating Protein ARAP3.","date":"2016","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/27311713","citation_count":11,"is_preprint":false},{"pmid":"22750419","id":"PMC_22750419","title":"Identification and structural basis for a novel interaction between Vav2 and Arap3.","date":"2012","source":"Journal of structural biology","url":"https://pubmed.ncbi.nlm.nih.gov/22750419","citation_count":10,"is_preprint":false},{"pmid":"16472652","id":"PMC_16472652","title":"Purification of ARAP3 and characterization of GAP activities.","date":"2006","source":"Methods in enzymology","url":"https://pubmed.ncbi.nlm.nih.gov/16472652","citation_count":6,"is_preprint":false},{"pmid":"25542002","id":"PMC_25542002","title":"ARAP3 functions in hematopoietic stem cells.","date":"2014","source":"PloS one","url":"https://pubmed.ncbi.nlm.nih.gov/25542002","citation_count":3,"is_preprint":false},{"pmid":"38734878","id":"PMC_38734878","title":"ARAP3 protects from excessive formylated peptide-induced microvascular leakage by acting on endothelial cells and neutrophils.","date":"2024","source":"The Journal of pathology","url":"https://pubmed.ncbi.nlm.nih.gov/38734878","citation_count":2,"is_preprint":false},{"pmid":"36674645","id":"PMC_36674645","title":"Structural Insights Uncover the Specific Phosphoinositide Recognition by the PH1 Domain of Arap3.","date":"2023","source":"International journal of molecular sciences","url":"https://pubmed.ncbi.nlm.nih.gov/36674645","citation_count":1,"is_preprint":false},{"pmid":"39207407","id":"PMC_39207407","title":"Genetic Variants in Genes Correlated to the PI3K/AKT Pathway: The Role of ARAP3, CDH5, KIF11 and RELN in Primary Lymphedema.","date":"2023","source":"Lymphology","url":"https://pubmed.ncbi.nlm.nih.gov/39207407","citation_count":1,"is_preprint":false},{"pmid":"32908855","id":"PMC_32908855","title":"Mutations in the ARAP3 Gene in Three Families with Primary Lymphedema Negative for Mutations in Known Lymphedema-Associated Genes.","date":"2020","source":"International journal of genomics","url":"https://pubmed.ncbi.nlm.nih.gov/32908855","citation_count":0,"is_preprint":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":14718,"output_tokens":5554,"usd":0.063732,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":13952,"output_tokens":5785,"usd":0.107192,"stage2_stop_reason":"end_turn"},"total_usd":0.170924,"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\": 2002,\n      \"finding\": \"ARAP3 is a specific PtdIns(3,4,5)P3/PtdIns(3,4)P2-stimulated Arf6 GAP both in vitro and in vivo, and both its Arf GAP and Rho GAP domains cooperate in mediating PI3K-dependent rearrangements in cell cytoskeleton and cell shape. ARAP3 was identified by selective capture on phosphoinositide affinity matrices from leukocyte extracts and has five PH domains.\",\n      \"method\": \"Phosphoinositide affinity matrix capture, mass spectrometry identification, in vitro and in vivo GAP activity assays\",\n      \"journal\": \"Molecular cell\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — in vitro biochemical reconstitution of GAP activity plus in vivo validation, replicated in subsequent studies\",\n      \"pmids\": [\"11804589\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2004,\n      \"finding\": \"ARAP3 functions as a RhoA-preferring Rho GAP (not other Rho family members) and is directly activated in vitro by GTP-bound Rap proteins binding to its Ras-binding domain (RBD). This activation is GTP-dependent and specific for Rap versus other Ras family members. PI3K activity was required for Rap-mediated activation in a cellular context, suggesting PtdIns(3,4,5)P3-dependent membrane translocation is required for subsequent Rap activation.\",\n      \"method\": \"In vitro GAP activity assays, direct binding assays with Rap proteins, cellular PI3K inhibition experiments\",\n      \"journal\": \"Current biology : CB\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — in vitro biochemical reconstitution with mutagenesis context, replicated in subsequent studies\",\n      \"pmids\": [\"15296756\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2004,\n      \"finding\": \"ARAP3 is tyrosine phosphorylated by Src-family kinases (SFKs) upon adhesion to fibronectin, growth factor stimulation, and co-expression with SFKs. Adhesion-induced phosphorylation was suppressed by SFK and PI3K inhibitors. ARAP3 inhibits cell spreading in a RhoGAP-dependent manner, reducing active RhoA and Rac1 levels. Mutation of phosphorylation sites Y1399 and Y1404 enhanced ARAP3 activities, indicating negative regulation by phosphorylation on these tyrosines.\",\n      \"method\": \"Co-expression with SFKs, pharmacological inhibitors, dominant-negative mutants, inducible expression, RhoA/Rac1 activity assays, site-directed mutagenesis\",\n      \"journal\": \"Journal of cell science\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — multiple orthogonal methods (pharmacological, genetic, biochemical) in a single study with specific mutagenesis\",\n      \"pmids\": [\"15546919\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2004,\n      \"finding\": \"ARAP3 deficiency impairs entry of anthrax protective antigen (PA) and its bound toxigenic moieties into human and mouse cells, identifying ARAP3 as a host factor essential for cellular internalization of anthrax toxin, consistent with its role in membrane vesicle trafficking.\",\n      \"method\": \"EST-based genome-wide gene inactivation screen, antisense expression, cell survival assay after PA-dependent toxin treatment\",\n      \"journal\": \"Proceedings of the National Academy of Sciences of the United States of America\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — genome-wide phenotypic screen with follow-up antisense validation in human and mouse cells, single lab\",\n      \"pmids\": [\"15569923\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2006,\n      \"finding\": \"ARAP3 is essential for lamellipodia formation after growth factor stimulation in endothelial cells. ARAP3-deficient cells show increased RhoA and Arf6 activities, are more rounded, display fine stress fibres, and cannot produce lamellipodia. Rac was activated but mislocalized in ARAP3-deficient cells, likely due to increased Arf6 activity. ARAP3 recruitment to sites of elevated PtdIns(3,4,5)P3 allows localized RhoA inactivation and Arf6 cycling.\",\n      \"method\": \"RNAi knockdown in endothelial cells, RhoA/Arf6/Rac activity assays, confocal microscopy of cell morphology and actin dynamics\",\n      \"journal\": \"Journal of cell science\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — RNAi loss-of-function with defined cellular phenotypes and GTPase activity measurements, replicated concept across multiple papers\",\n      \"pmids\": [\"16418224\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2006,\n      \"finding\": \"ARAP3's domain structure includes five PH domains, an Arf GAP domain, three ankyrin repeats, a Rho GAP domain, and a Ras association domain. It is a PtdIns(3,4,5)P3-dependent GAP for Arf6 in vitro and in vivo, and a Rap-GTP-activated RhoA GAP in vitro requiring direct interaction between ARAP3 and Rap-GTP; in vivo, PtdIns(3,4,5)P3 is required to enable RhoA GAP activation by Rap-GTP.\",\n      \"method\": \"Protein purification, in vitro GAP activity assays, overexpression phenotype analysis in PAE cells\",\n      \"journal\": \"Methods in enzymology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — purified protein reconstitution with in vitro GAP assays, confirmed by multiple earlier and subsequent studies\",\n      \"pmids\": [\"16472652\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2007,\n      \"finding\": \"ARAP3 interacts with the PI(3,4,5)P3 phosphatase SHIP2 through a SAM domain-mediated heterodimeric interaction. The SAM domain of ARAP3 and the SAM domain of SHIP2 show specificity for heterodimeric interaction in vitro. This interaction was confirmed with endogenous proteins.\",\n      \"method\": \"Yeast two-hybrid screen, endogenous co-immunoprecipitation, in vitro SAM domain binding assay\",\n      \"journal\": \"Cellular signalling\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — reciprocal endogenous Co-IP plus in vitro domain-specific binding, multiple methods in one study\",\n      \"pmids\": [\"17314030\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2009,\n      \"finding\": \"ARAP3 binds PtdIns(3,4,5)P3 through an unusual mechanism requiring the N-terminal tandem PH domains plus an N-terminal linker region. No single PH domain is sufficient for binding. The N-terminal SAM domain further contributes to substantial binding. Site-directed mutagenesis of either N-terminal PH domain greatly reduces PtdIns(3,4,5)P3 binding, and deletion of any single PH domain abolishes binding.\",\n      \"method\": \"PtdIns(3,4,5)P3 binding assays with truncation and point mutants, site-directed mutagenesis\",\n      \"journal\": \"Cellular signalling\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — systematic mutagenesis and domain deletion analysis with direct lipid binding assays, single lab\",\n      \"pmids\": [\"19786092\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2009,\n      \"finding\": \"The NMR solution structure of Arap3-SAM was determined, and heterodimeric interaction with Ship2-SAM was characterized. Arap3-SAM associates with Ship2-SAM using a binding mode common to other SAM domain pairs, identical to Ship2-SAM/EphA2-SAM interaction. Key structural features mediating SAM-SAM interactions were identified.\",\n      \"method\": \"NMR solution structure determination, ITC, mutagenesis, molecular modeling\",\n      \"journal\": \"BMC structural biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — NMR structure determination plus ITC thermodynamic validation and mutagenesis in one study\",\n      \"pmids\": [\"19765305\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2010,\n      \"finding\": \"ARAP3 deletion in mice causes embryonic death in mid-gestation due to an endothelial cell-autonomous defect in sprouting angiogenesis. Knock-in mice with an ARAP3 point mutant that cannot be activated by PtdIns(3,4,5)P3 have similar angiogenesis defects, establishing that PI3Kα signals through ARAP3 (via PtdIns(3,4,5)P3 activation) to control RhoA and Arf6 during angiogenesis.\",\n      \"method\": \"Arap3 knockout mouse, PtdIns(3,4,5)P3-binding point mutant knock-in mouse, ex vivo explant assays, genetic epistasis\",\n      \"journal\": \"Science signaling\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — two independent mouse genetic models (KO and point-mutant KI) with ex vivo phenotype confirmation, establishing pathway position\",\n      \"pmids\": [\"20978237\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2010,\n      \"finding\": \"ARAP3 inactivates RhoA downstream of Rap1 during neurite outgrowth in PC12 cells in response to bFGF. Dominant-negative ARAP3 and dominant-negative Rap1 both reduced neurite formation, placing ARAP3 as a Rap1 effector that inactivates RhoA to enable neurite outgrowth.\",\n      \"method\": \"Dominant-negative ARAP3 expression in PC12 cells, GTP-RhoA activity assays, neurite outgrowth quantification\",\n      \"journal\": \"Journal of cellular physiology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 / Moderate — dominant-negative approach with phenotypic readout, replicated with NGF in a companion paper\",\n      \"pmids\": [\"20578246\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2010,\n      \"finding\": \"In PC12 cells responding to NGF, ARAP3 acts downstream of Rap1 to inactivate RhoA and enable neurite outgrowth. Dominant-negative ARAP3 prevented RhoA inactivation and abolished neurite formation. RhoA was co-immunoprecipitated with Rap1, and NGF activated Rap1.\",\n      \"method\": \"Dominant-negative expression, GTP-RhoA activity assays, co-immunoprecipitation of RhoA and Rap1, neurite outgrowth quantification\",\n      \"journal\": \"Experimental & molecular medicine\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 / Moderate — dominant-negative approach with Co-IP and activity assays, replicated the bFGF finding in the same cellular model with NGF\",\n      \"pmids\": [\"20200473\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2010,\n      \"finding\": \"ARAP3 overexpression in scirrhous gastric carcinoma cells inhibits peritoneal dissemination by regulating cell attachment to ECM and invasion. These effects required a functional Rho-GAP domain and the C-terminal tyrosine residues (Y1399/Y1404) phosphorylated by Src, but were suppressed by mutations in either the RhoGAP domain or these tyrosines.\",\n      \"method\": \"Overexpression in cancer cell lines, peritoneal dissemination assay, cell adhesion and invasion assays, RhoGAP domain mutants and tyrosine phosphorylation site mutants\",\n      \"journal\": \"Oncogene\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — domain mutagenesis with defined cellular phenotypes, single lab with multiple mutant analyses\",\n      \"pmids\": [\"21076469\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2011,\n      \"finding\": \"ARAP3 functions downstream of Rap in neutrophils to modulate β2 integrin affinity and avidity. ARAP3-deficient neutrophils are preactivated, show increased β2 integrin inside-out signaling, hyperresponsive adhesion-dependent functions (ROS formation, adhesion, spreading, granule release), and defective integrin-dependent chemotaxis. ARAP3 guards neutrophils in their quiescent state.\",\n      \"method\": \"Arap3 conditional knockout mouse neutrophils, β2 integrin activation assays, flow assays, intravital microscopy, in vitro chemotaxis\",\n      \"journal\": \"Blood\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — conditional KO mouse with multiple orthogonal functional readouts both in vitro and in vivo\",\n      \"pmids\": [\"21490342\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"PI3K regulates β2 integrin activity in neutrophils specifically through its effector ARAP3: neutrophils from ARAP3 PH domain point mutant knock-in mice (R302,303A, uncoupled from PI3K activation) show increased β2 integrin inside-out signaling and disturbed adhesion-dependent responses, with reduced neutrophil recruitment in vivo. Neutrophil chemotaxis was also affected.\",\n      \"method\": \"ARAP3 PH domain point mutant knock-in mouse, β2 integrin activation assays, in vitro chemotaxis, in vivo peritonitis and arthritis models, bone marrow chimeras\",\n      \"journal\": \"Journal of immunology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — knock-in mouse with a specific point mutation decoupling PI3K input, multiple in vitro and in vivo assays, establishes pathway position\",\n      \"pmids\": [\"23180820\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"Arap3-SAM interacts with the first SAM domain of Odin (Odin-Sam1) with low micromolar affinity. NMR, SPR, ITC, and molecular docking revealed a heterotypic SAM-SAM binding topology common to other SAM domain complexes, identifying structural determinants for the interaction.\",\n      \"method\": \"NMR spectroscopy, SPR, ITC, molecular docking\",\n      \"journal\": \"Chembiochem\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — multiple biophysical methods (NMR, SPR, ITC) from a single lab characterizing a novel interaction\",\n      \"pmids\": [\"23239578\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"Vav2 SH2 domain interacts directly with phosphorylated Y1403 and Y1408 (corresponding to the Src-phosphorylated tyrosines) within the C-terminal region of Arap3, with dissociation constants of ~0.27 and ~1.40 μM respectively. The solution structures of Vav2 SH2 domain free and in complex with pY1408 peptide were determined, revealing the structural basis for this recognition.\",\n      \"method\": \"ITC, NMR chemical shift perturbation, NMR solution structure determination, Co-IP in vivo\",\n      \"journal\": \"Journal of structural biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — NMR structure plus ITC quantification and in vivo Co-IP validation in one study\",\n      \"pmids\": [\"22750419\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"ARAP3 is necessary for lymphatic vascular development in mice and zebrafish and acts as a mediator of the cellular response to Vegfc signaling in lymphatic endothelial cells. ARAP3 is downregulated in HLT mouse aberrant dermal lymphatic vessels, positioning it downstream of Vegfc in lymphangiogenesis.\",\n      \"method\": \"Mouse model gene expression profiling, zebrafish functional analysis, in vitro Vegfc signaling assays, in vivo lymphatic vessel analysis\",\n      \"journal\": \"Human molecular genetics\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — functional analysis in two model organisms with in vitro pathway placement, single lab\",\n      \"pmids\": [\"24163130\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"Crystal structure of RhoA in complex with the RhoGAP domain of ARAP3 was solved, revealing the molecular interface. In vitro GTPase activity assays and ITC experiments identified crucial residues affecting RhoGAP catalytic activity and substrate specificity, explaining why ARAP3 preferentially activates RhoA over Rac1 and Cdc42.\",\n      \"method\": \"X-ray crystallography, in vitro GTPase activity assays, ITC, mutagenesis\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — crystal structure plus biochemical reconstitution with mutagenesis and calorimetry in one study\",\n      \"pmids\": [\"27311713\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"The first PH domain of Arap3 (PH1) is sufficient to interact with PI(3,4,5)P3 (and with lower affinity PI(4,5)P2). The crystal structure of Arap3-PH1 in apo form and in complex with diC4-PI(3,4,5)P3 was determined, revealing the structural basis for specific phosphoinositide recognition. PI(3,4,5)P3-binding by PH1 is essential for ARAP3's ability to inhibit breast cancer cell invasion.\",\n      \"method\": \"Liposome pull-down, SPR, NMR, X-ray crystallography of apo and PI(3,4,5)P3-bound PH1, cell invasion assays with PH1 mutants\",\n      \"journal\": \"International journal of molecular sciences\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — crystal structure plus multiple orthogonal biophysical methods and functional cell assay validating the structural finding\",\n      \"pmids\": [\"36674645\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"ARAP3 protects against formylated peptide-induced microvascular permeability through both endothelial cells and neutrophils. In vitro, Arap3-/- endothelial monolayers show enhanced permeability due to upregulated FPR1 and enhanced VE-cadherin internalisation. In vivo, loss of ARAP3 leads to excessive microvascular leakage and neutrophil extracellular trap (NET) formation; pharmacological inhibition of NET formation abrogated the excessive leakage.\",\n      \"method\": \"Arap3 knockout mouse, endothelial monolayer permeability assays, adoptive transfer experiments, pharmacological NET inhibition, bronchoalveolar lavage analysis, influenza infection model\",\n      \"journal\": \"The Journal of pathology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — multiple in vitro and in vivo approaches with mechanistic dissection of cell types and molecular events, single lab\",\n      \"pmids\": [\"38734878\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"ARAP3 is a dual GTPase-activating protein for Arf6 and RhoA that functions as a PI3K effector: PtdIns(3,4,5)P3 (generated by PI3Kα) recruits ARAP3 to the plasma membrane via its tandem N-terminal PH domains (structurally characterized) and catalytically activates its Arf6 GAP activity, while its RhoA GAP activity is further activated by direct binding of GTP-Rap to its RBD domain; Src-family kinases phosphorylate C-terminal tyrosines (Y1399/Y1404) to negatively regulate ARAP3 and recruit Vav2 via its SH2 domain; the SAM domain mediates heterodimeric interactions with SHIP2 and Odin; downstream, ARAP3 controls cell shape, lamellipodia formation, β2 integrin activity in neutrophils, sprouting angiogenesis, lymphangiogenesis, and vascular permeability by coordinating localized inactivation of RhoA and cycling of Arf6 at sites of PI3K signaling.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"ARAP3 is a phosphoinositide-regulated dual GTPase-activating protein that converts localized PI3K signaling into coordinated control of Arf6 and RhoA, thereby shaping the actin cytoskeleton, cell adhesion, and vascular morphogenesis [#0, #5]. It is a PtdIns(3,4,5)P3/PtdIns(3,4)P2-stimulated Arf6 GAP and a RhoA-preferring Rho GAP whose Rho GAP activity is switched on by direct binding of GTP-loaded Rap to its Ras-binding domain, with PtdIns(3,4,5)P3-dependent membrane recruitment required to license this Rap-driven activation in cells [#0, #1, #5]; the structural basis for its RhoA preference over Rac1 and Cdc42 was resolved in a RhoA-RhoGAP domain co-crystal [#18]. Membrane recruitment depends on an unusual lipid-binding mode in which tandem N-terminal PH domains, an N-terminal linker, and the SAM domain cooperate, with the first PH domain alone sufficient for specific PtdIns(3,4,5)P3 recognition [#7, #19]. ARAP3 is negatively regulated by Src-family kinase phosphorylation of C-terminal tyrosines (Y1399/Y1404), which creates a docking site bound by the Vav2 SH2 domain [#2, #16], while its SAM domain mediates heterodimeric interactions with the PtdIns(3,4,5)P3 phosphatase SHIP2 and with Odin [#6, #8, #15]. Through these activities ARAP3 enables lamellipodia formation, neurite outgrowth downstream of Rap1, and restrains cell spreading, adhesion, and invasion [#2, #4, #10, #12]. In vivo it acts as the endothelial PI3Kα effector required for sprouting angiogenesis and lymphangiogenesis, guards neutrophils in a quiescent state by limiting β2 integrin inside-out signaling, and protects against microvascular permeability and NET formation [#9, #13, #14, #20].\",\n  \"teleology\": [\n    {\n      \"year\": 2002,\n      \"claim\": \"Established ARAP3 as a phosphoinositide-responsive enzyme by showing it is a PtdIns(3,4,5)P3-stimulated Arf6 GAP whose Arf and Rho GAP domains together drive PI3K-dependent cytoskeletal and cell-shape changes, linking lipid signaling to GTPase control.\",\n      \"evidence\": \"Phosphoinositide affinity capture and mass spectrometry from leukocyte extracts with in vitro and in vivo GAP assays\",\n      \"pmids\": [\"11804589\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not define the structural basis for lipid binding\", \"Rho GAP substrate specificity not yet resolved\"]\n    },\n    {\n      \"year\": 2004,\n      \"claim\": \"Defined the Rho GAP arm as RhoA-specific and showed it is allosterically activated by direct binding of GTP-Rap to the RBD, with PI3K required in cells, establishing ARAP3 as a coincidence detector of Rap-GTP and PtdIns(3,4,5)P3.\",\n      \"evidence\": \"In vitro GAP and direct Rap-binding assays plus cellular PI3K inhibition\",\n      \"pmids\": [\"15296756\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Structural interface of Rap-RBD binding not determined\", \"How PtdIns(3,4,5)P3 and Rap inputs are integrated mechanistically unresolved\"]\n    },\n    {\n      \"year\": 2004,\n      \"claim\": \"Identified Src-family kinase phosphorylation of C-terminal tyrosines Y1399/Y1404 as a negative regulatory input, since mutating these sites enhanced ARAP3 activity and adhesion-dependent inhibition of spreading.\",\n      \"evidence\": \"SFK co-expression, pharmacological inhibitors, site-directed mutagenesis, RhoA/Rac1 activity assays\",\n      \"pmids\": [\"15546919\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Downstream effector of phosphorylated tyrosines not identified at this stage\", \"In vivo relevance of phosphoregulation not tested\"]\n    },\n    {\n      \"year\": 2004,\n      \"claim\": \"Implicated ARAP3 in membrane internalization by showing its loss impairs anthrax protective antigen entry, consistent with a vesicle-trafficking role.\",\n      \"evidence\": \"Genome-wide gene inactivation screen with antisense validation and toxin survival assay\",\n      \"pmids\": [\"15569923\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Mechanistic link between ARAP3 GAP activity and toxin uptake not established\", \"Single-lab phenotypic screen without enzymatic dissection\"]\n    },\n    {\n      \"year\": 2006,\n      \"claim\": \"Demonstrated the cellular consequence of coordinated GTPase control: ARAP3 is required for growth-factor-induced lamellipodia, with its loss raising RhoA and Arf6 activity and mislocalizing Rac.\",\n      \"evidence\": \"RNAi in endothelial cells with RhoA/Arf6/Rac activity assays and confocal morphology\",\n      \"pmids\": [\"16418224\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not separate Arf6 versus RhoA contributions to lamellipodia\", \"Recruitment kinetics at PtdIns(3,4,5)P3 sites not measured\"]\n    },\n    {\n      \"year\": 2007,\n      \"claim\": \"Revealed a protein-interaction layer by identifying a SAM-domain heterodimer between ARAP3 and the PtdIns(3,4,5)P3 phosphatase SHIP2, suggesting spatial coupling of lipid production and turnover.\",\n      \"evidence\": \"Yeast two-hybrid, endogenous reciprocal Co-IP, in vitro SAM binding\",\n      \"pmids\": [\"17314030\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Functional consequence of the ARAP3-SHIP2 complex for signaling not tested\", \"Stoichiometry and cellular context of the interaction unknown\"]\n    },\n    {\n      \"year\": 2009,\n      \"claim\": \"Defined the unusual membrane-targeting mechanism, showing PtdIns(3,4,5)P3 binding requires cooperation of tandem PH domains, an N-terminal linker, and the SAM domain rather than a single PH module.\",\n      \"evidence\": \"Lipid-binding assays with truncations and point mutants\",\n      \"pmids\": [\"19786092\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"High-resolution structure of the bound state not yet available\", \"Conflicts with later finding that PH1 alone suffices needed reconciling\"]\n    },\n    {\n      \"year\": 2009,\n      \"claim\": \"Provided the structural basis for the SHIP2 interaction by solving the Arap3-SAM NMR structure and showing it uses a canonical SAM-SAM binding mode shared with EphA2.\",\n      \"evidence\": \"NMR solution structure, ITC, mutagenesis, modeling\",\n      \"pmids\": [\"19765305\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not establish in vivo signaling output of the SAM heterodimer\", \"Competition among SAM partners not addressed\"]\n    },\n    {\n      \"year\": 2010,\n      \"claim\": \"Positioned ARAP3 genetically as the PI3Kα effector for angiogenesis by showing both knockout and a PtdIns(3,4,5)P3-uncoupling knock-in mouse cause endothelial-autonomous sprouting defects and mid-gestation lethality.\",\n      \"evidence\": \"Arap3 knockout and lipid-binding point-mutant knock-in mice with ex vivo explants and genetic epistasis\",\n      \"pmids\": [\"20978237\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Relative in vivo contributions of Arf6 versus RhoA control not dissected\", \"Downstream cytoskeletal effectors in sprouting not mapped\"]\n    },\n    {\n      \"year\": 2010,\n      \"claim\": \"Extended the Rap1-effector role to neuronal differentiation, showing ARAP3 inactivates RhoA downstream of Rap1 to permit bFGF- and NGF-induced neurite outgrowth.\",\n      \"evidence\": \"Dominant-negative ARAP3 in PC12 cells with GTP-RhoA assays, Rap1-RhoA Co-IP, and neurite quantification\",\n      \"pmids\": [\"20578246\", \"20200473\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Relied on dominant-negative rather than loss-of-function\", \"Endogenous ARAP3 requirement in neurons not confirmed\"]\n    },\n    {\n      \"year\": 2010,\n      \"claim\": \"Linked ARAP3 to suppression of cancer cell invasion, showing overexpression inhibits gastric carcinoma peritoneal dissemination in a manner dependent on both the Rho GAP domain and the Src-target tyrosines.\",\n      \"evidence\": \"Overexpression with domain and tyrosine mutants in dissemination, adhesion, and invasion assays\",\n      \"pmids\": [\"21076469\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Overexpression-based; endogenous tumor-suppressive role not tested\", \"Connection to Arf6 cycling in invasion not examined\"]\n    },\n    {\n      \"year\": 2011,\n      \"claim\": \"Defined a physiological immune role, showing ARAP3 acts downstream of Rap to keep neutrophils quiescent by restraining β2 integrin affinity and avidity.\",\n      \"evidence\": \"Conditional knockout neutrophils with integrin activation, flow, intravital, and chemotaxis assays\",\n      \"pmids\": [\"21490342\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not separate which GAP activity controls integrin signaling\", \"Molecular link from ARAP3 to inside-out signaling unmapped\"]\n    },\n    {\n      \"year\": 2012,\n      \"claim\": \"Pinned the neutrophil phenotype to PI3K input by showing a PH-domain point-mutant knock-in (R302,303A) uncoupled from PtdIns(3,4,5)P3 recapitulates β2 integrin dysregulation and impaired recruitment in vivo.\",\n      \"evidence\": \"PH-domain point-mutant knock-in mouse with integrin assays, chemotaxis, peritonitis/arthritis models, bone marrow chimeras\",\n      \"pmids\": [\"23180820\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Downstream GTPase events controlling integrin activation not resolved\", \"Cell-intrinsic versus systemic effects only partly separated\"]\n    },\n    {\n      \"year\": 2012,\n      \"claim\": \"Resolved the structural basis of phosphotyrosine readout, showing the Vav2 SH2 domain directly binds the Src-phosphorylated C-terminal tyrosines with micromolar affinity, identifying a recruited partner of inhibited ARAP3.\",\n      \"evidence\": \"ITC, NMR chemical shift perturbation, NMR structure of Vav2 SH2-pY1408 complex, in vivo Co-IP\",\n      \"pmids\": [\"22750419\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Functional consequence of Vav2 recruitment to ARAP3 not established\", \"Whether recruitment alters ARAP3 GAP output unknown\"]\n    },\n    {\n      \"year\": 2012,\n      \"claim\": \"Characterized a second SAM-domain partner, defining the heterotypic Arap3-SAM/Odin-Sam1 interface and binding topology.\",\n      \"evidence\": \"NMR, SPR, ITC, molecular docking\",\n      \"pmids\": [\"23239578\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Cellular and physiological role of the ARAP3-Odin complex untested\", \"How Odin and SHIP2 compete for the same SAM domain unresolved\"]\n    },\n    {\n      \"year\": 2013,\n      \"claim\": \"Broadened the vascular role to lymphatics, placing ARAP3 downstream of Vegfc as a mediator required for lymphangiogenesis in mouse and zebrafish.\",\n      \"evidence\": \"Mouse expression profiling, zebrafish functional analysis, in vitro Vegfc assays, in vivo lymphatic analysis\",\n      \"pmids\": [\"24163130\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"GTPase targets in lymphatic endothelium not dissected\", \"Direct Vegfc-to-ARAP3 signaling link not biochemically defined\"]\n    },\n    {\n      \"year\": 2016,\n      \"claim\": \"Explained RhoA substrate preference at atomic resolution by solving the RhoA-RhoGAP domain complex and identifying residues governing catalysis and specificity over Rac1 and Cdc42.\",\n      \"evidence\": \"X-ray crystallography, GTPase assays, ITC, mutagenesis\",\n      \"pmids\": [\"27311713\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not capture the Rap-activated conformation\", \"Full-length autoregulated state not structurally resolved\"]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"Refined the lipid-recognition model by showing PH1 alone is sufficient for specific PtdIns(3,4,5)P3 binding, solving apo and lipid-bound structures and tying PH1 binding to inhibition of breast cancer invasion.\",\n      \"evidence\": \"Liposome pull-down, SPR, NMR, crystallography of PH1, cell invasion assays with PH1 mutants\",\n      \"pmids\": [\"36674645\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Relationship between PH1-only binding and earlier multi-domain requirement not fully reconciled\", \"Structure of all five PH domains together unsolved\"]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Established a barrier-protective function, showing ARAP3 limits microvascular permeability through both endothelial cells (restraining FPR1 and VE-cadherin internalization) and neutrophils (limiting NET formation).\",\n      \"evidence\": \"Arap3 knockout mouse, endothelial permeability assays, adoptive transfer, NET inhibition, influenza model\",\n      \"pmids\": [\"38734878\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Direct GAP-substrate events controlling VE-cadherin trafficking not pinpointed\", \"Mechanism connecting ARAP3 to FPR1 expression unknown\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How the multiple inputs (PtdIns(3,4,5)P3 binding, Rap-GTP, Src phosphorylation, SAM partners) are integrated to set the timing and magnitude of Arf6 versus RhoA inactivation at a given membrane site remains unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"High\",\n      \"gaps\": [\"No full-length autoinhibited structure\", \"Functional output of SHIP2, Odin, and Vav2 binding not mechanistically integrated\", \"Quantitative model of dual-GAP coordination in vivo lacking\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0140096\", \"supporting_discovery_ids\": [0, 1, 5, 18]},\n      {\"term_id\": \"GO:0098772\", \"supporting_discovery_ids\": [0, 1, 5, 18]},\n      {\"term_id\": \"GO:0008289\", \"supporting_discovery_ids\": [0, 7, 19]},\n      {\"term_id\": \"GO:0060089\", \"supporting_discovery_ids\": [1, 10, 14]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005886\", \"supporting_discovery_ids\": [0, 4, 9]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-162582\", \"supporting_discovery_ids\": [0, 1, 9]},\n      {\"term_id\": \"R-HSA-168256\", \"supporting_discovery_ids\": [13, 14, 20]},\n      {\"term_id\": \"R-HSA-1266738\", \"supporting_discovery_ids\": [9, 17]}\n    ],\n    \"complexes\": [],\n    \"partners\": [\"RHOA\", \"ARF6\", \"RAP1\", \"SHIP2\", \"INPPL1\", \"VAV2\", \"ANKS1A\", \"SRC\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":6,"faith_total":6,"faith_pct":100.0}}