{"gene":"ESAM","run_date":"2026-06-09T23:54:43","timeline":{"discoveries":[{"year":2004,"finding":"ESAM directly binds the multidomain adaptor protein MAGI-1 via a PDZ domain-mediated interaction at its C-terminal sequence. This interaction was confirmed by yeast two-hybrid screen, pull-down experiments, and co-immunoisolation from transfected CHO cells. ESAM recruits MAGI-1 to cell-cell contacts; in CHO cells, MAGI-1 localization to cell contacts required the presence of ESAM.","method":"Yeast two-hybrid screen, pull-down assay, co-immunoprecipitation from transfected CHO cells, colocalization in HUVECs and mouse endothelium","journal":"Experimental cell research","confidence":"High","confidence_rationale":"Tier 2 / Strong — reciprocal binding confirmed by multiple orthogonal methods (yeast two-hybrid, pulldown, Co-IP, localization rescue) in a single focused study","pmids":["15383320"],"is_preprint":false},{"year":2006,"finding":"ESAM at endothelial tight junctions supports neutrophil extravasation: ESAM-/- mice showed ~50% reduction in leukocyte extravasation in cremaster muscle by intravital microscopy without affecting rolling/adhesion, and ~70% reduction in neutrophil migration into inflamed peritoneum at 2 h. Platelet depletion did not abolish this effect, indicating endothelial ESAM is the relevant pool. Knockdown of ESAM in endothelial cells reduced activated Rho GTPase levels. VEGF-induced vascular permeability was also reduced in ESAM-/- mice.","method":"ESAM knockout mouse model, intravital microscopy, peritonitis inflammation model, siRNA knockdown in endothelial cells, Rho activation assay, VEGF permeability assay","journal":"The Journal of experimental medicine","confidence":"High","confidence_rationale":"Tier 2 / Strong — clean KO with multiple defined phenotypic readouts (intravital microscopy, permeability assay), platelet depletion epistasis, and Rho activity measurement in a single rigorous study","pmids":["16818677"],"is_preprint":false},{"year":2009,"finding":"Following platelet activation, ESAM localizes to junctions between adjacent platelets. ESAM-/- mice formed larger thrombi and achieved more stable hemostasis than wild-type mice. ESAM-/- platelets aggregated at lower agonist concentrations and were more resistant to disaggregation, while calcium mobilization, αIIbβ3 activation, alpha-granule secretion, and platelet spreading were normal. Using a PDZ domain array, the scaffold protein NHERF-1 was identified as an ESAM binding partner, associating with ESAM in both resting and activated platelets.","method":"ESAM knockout mouse model, laser injury thrombosis model, tail transection hemostasis assay, in vitro platelet aggregation, PDZ domain array, co-immunoprecipitation","journal":"Journal of thrombosis and haemostasis : JTH","confidence":"High","confidence_rationale":"Tier 2 / Strong — KO with multiple functional phenotypic readouts (in vivo thrombosis, in vitro aggregation), PDZ array plus Co-IP for binding partner identification, single lab with multiple orthogonal methods","pmids":["19740102"],"is_preprint":false},{"year":2019,"finding":"ESAM is required for endothelial barrier integrity specifically in the lung; ESAM gene inactivation enhanced vascular permeability in lung but not heart, skin, or brain. Combined loss of ESAM and VE-cadherin (by antibody blockade or induced gene inactivation) caused immediate lethality within 30 minutes, disrupted endothelial junctions ultrastructurally, and caused massive blood coagulation in the lung — effects not seen with loss of JAM-A or PECAM-1 combined with VE-cadherin blockade. Mechanistically, platelet ESAM was excluded as the relevant pool, and cytoplasmic signaling domains of ESAM were found not to contribute to this phenotype.","method":"Inducible gene knockout mouse models, antibody blocking in vivo, vascular permeability assays, electron microscopy ultrastructural analysis, genetic epistasis (double KO)","journal":"Arteriosclerosis, thrombosis, and vascular biology","confidence":"High","confidence_rationale":"Tier 2 / Strong — genetic epistasis with multiple KO combinations, ultrastructural validation, tissue-specific permeability assays, negative controls (JAM-A, PECAM-1) in a single rigorous study","pmids":["31826650"],"is_preprint":false},{"year":2012,"finding":"ESAM expression levels on HSCs mirror the shift between quiescence and active proliferation/self-renewal. ESAMhi HSCs are actively dividing yet retain high long-term reconstituting capacity. ESAM-/- mice showed severe and prolonged bone marrow suppression after 5-fluorouracil treatment, indicating ESAM is functionally indispensable for HSC-mediated re-establishment of homeostatic hematopoiesis. ESAMhi HSCs were located near vascular endothelium after BM injury. NF-κB and topoisomerase II levels correlated with ESAM upregulation.","method":"ESAM knockout mouse model, 5-FU bone marrow injury model, cell cycle analysis, long-term reconstitution transplantation assay, immunohistochemistry","journal":"Journal of immunology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — clean KO with defined hematopoietic reconstitution phenotype and cell-cycle readout, single lab","pmids":["22649198"],"is_preprint":false},{"year":2023,"finding":"Bi-allelic loss-of-function variants in ESAM cause defective in vitro tubulogenesis of endothelial colony-forming cells, recapitulating the vascular phenotype seen in null mice, and result in absence of ESAM expression in capillary endothelial cells of damaged brain. This establishes ESAM as a tight junction molecule essential for brain vascular integrity.","method":"Human genetics (exome sequencing), in vitro tubulogenesis assay of patient-derived endothelial colony-forming cells, immunostaining of patient brain tissue","journal":"American journal of human genetics","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — functional in vitro assay with patient-derived cells plus tissue immunostaining, single study with orthogonal approaches","pmids":["36996813"],"is_preprint":false},{"year":2009,"finding":"In resting platelets, ESAM is stored in alpha granules and translocates to the platelet surface following platelet activation, localizing specifically to platelet-platelet contact junctions.","method":"Immunofluorescence localization in activated vs. resting platelets","journal":"Journal of thrombosis and haemostasis : JTH","confidence":"Medium","confidence_rationale":"Tier 3 / Moderate — direct localization experiment with functional context, single lab, imaging-based","pmids":["19740102"],"is_preprint":false}],"current_model":"ESAM is an immunoglobulin-superfamily transmembrane protein localized at endothelial tight junctions and platelet alpha granules (translocating to platelet-platelet contacts upon activation) that maintains vascular barrier integrity — particularly in the lung in cooperation with VE-cadherin — supports neutrophil extravasation by activating Rho GTPase at endothelial junctions, limits thrombus growth via NHERF-1 scaffold interactions at platelet contacts, and anchors the adaptor protein MAGI-1 at endothelial cell contacts through a C-terminal PDZ domain interaction; it is also functionally required for hematopoietic stem cell-mediated reconstitution of homeostatic hematopoiesis after bone marrow injury."},"narrative":{"mechanistic_narrative":"ESAM is an immunoglobulin-superfamily adhesion molecule that operates at endothelial junctions and at platelet contacts to regulate vascular barrier integrity, inflammatory cell trafficking, and thrombus stability [PMID:16818677, PMID:31826650]. At endothelial tight junctions ESAM anchors the multidomain scaffold MAGI-1 through a C-terminal PDZ-mediated interaction, and ESAM is required to recruit MAGI-1 to cell-cell contacts [PMID:15383320]. Endothelial ESAM supports neutrophil extravasation downstream of an activated Rho GTPase signal at the junction — acting on the diapedesis step rather than rolling or adhesion — and contributes to VEGF-induced vascular permeability [PMID:16818677]. ESAM maintains barrier integrity in a tissue-restricted manner, with permeability defects in the lung; combined loss of ESAM and VE-cadherin causes ultrastructural junction disruption, pulmonary coagulation, and rapid lethality, defining a cooperative role with VE-cadherin not shared by JAM-A or PECAM-1 [PMID:31826650]. In platelets, ESAM is stored in alpha granules and translocates to platelet-platelet contact junctions upon activation, where it binds the scaffold NHERF-1 and limits thrombus growth and stability without altering calcium mobilization, integrin activation, or granule secretion [PMID:19740102]. ESAM is also functionally indispensable for hematopoietic stem cell-mediated re-establishment of homeostatic hematopoiesis after bone marrow injury [PMID:22649198]. Bi-allelic loss-of-function variants in ESAM impair endothelial tubulogenesis and cause defective brain vascular integrity in humans [PMID:36996813].","teleology":[{"year":2004,"claim":"Established the first molecular partner of ESAM, showing how an endothelial junctional protein could organize an intracellular scaffold at cell contacts.","evidence":"Yeast two-hybrid, pull-down, and Co-IP in transfected CHO cells with colocalization in HUVECs and mouse endothelium","pmids":["15383320"],"confidence":"High","gaps":["Does not define the downstream signaling consequence of MAGI-1 recruitment","Functional role of the ESAM-MAGI-1 complex in vivo not tested"]},{"year":2006,"claim":"Resolved which step of leukocyte trafficking ESAM controls and linked endothelial ESAM to Rho GTPase activation, distinguishing diapedesis from adhesion.","evidence":"ESAM-/- mice, intravital microscopy, peritonitis model, endothelial siRNA knockdown, Rho activation assay, and VEGF permeability assay","pmids":["16818677"],"confidence":"High","gaps":["Mechanism connecting ESAM to Rho activation not defined","Whether MAGI-1 mediates the Rho effect untested"]},{"year":2009,"claim":"Defined a platelet-intrinsic role for ESAM in limiting thrombus growth and identified its platelet scaffold partner, separating it from the general platelet activation machinery.","evidence":"ESAM-/- mice, laser injury thrombosis and tail transection assays, in vitro aggregation, PDZ domain array, and Co-IP; immunofluorescence of resting vs activated platelets","pmids":["19740102"],"confidence":"High","gaps":["Mechanism by which NHERF-1 binding restrains aggregation not resolved","Signaling output of ESAM at platelet contacts unknown"]},{"year":2012,"claim":"Connected ESAM expression to HSC proliferative state and demonstrated it is functionally required for regenerative hematopoiesis after injury.","evidence":"ESAM-/- mice, 5-FU bone marrow injury, cell-cycle analysis, long-term reconstitution transplantation, and immunohistochemistry","pmids":["22649198"],"confidence":"Medium","gaps":["Molecular mechanism of ESAM in HSC self-renewal not defined","Relationship between NF-kB/topoisomerase II correlation and ESAM function unestablished"]},{"year":2019,"claim":"Showed ESAM cooperates with VE-cadherin for barrier integrity in a tissue-specific (lung) manner, and that its cytoplasmic signaling domains are dispensable for this phenotype.","evidence":"Inducible KO mice, in vivo antibody blockade, tissue-specific permeability assays, electron microscopy, and genetic epistasis with VE-cadherin, JAM-A, and PECAM-1","pmids":["31826650"],"confidence":"High","gaps":["Molecular basis of ESAM/VE-cadherin cooperation unresolved","Why the phenotype is lung-restricted not explained"]},{"year":2023,"claim":"Provided human genetic evidence that ESAM loss of function causes defective endothelial tubulogenesis and brain vascular pathology, translating mouse phenotypes to disease.","evidence":"Exome sequencing, in vitro tubulogenesis of patient endothelial colony-forming cells, and patient brain immunostaining","pmids":["36996813"],"confidence":"Medium","gaps":["Mechanism linking ESAM loss to tubulogenesis failure not defined","Genotype-phenotype correlation across patients limited"]},{"year":null,"claim":"How ESAM's junctional scaffold interactions (MAGI-1, NHERF-1) mechanistically couple to Rho GTPase signaling, VE-cadherin cooperation, and HSC regeneration remains unresolved.","evidence":"","pmids":[],"confidence":"Medium","gaps":["No structural model of ESAM-scaffold complexes","Signaling pathway downstream of ESAM at junctions not mapped","Tissue specificity of barrier function unexplained"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0098631","term_label":"cell adhesion mediator activity","supporting_discovery_ids":[1,2,3]},{"term_id":"GO:0060090","term_label":"molecular adaptor activity","supporting_discovery_ids":[0,2]}],"localization":[{"term_id":"GO:0005886","term_label":"plasma membrane","supporting_discovery_ids":[1,3,6]},{"term_id":"GO:0031410","term_label":"cytoplasmic vesicle","supporting_discovery_ids":[6]}],"pathway":[{"term_id":"R-HSA-168256","term_label":"Immune System","supporting_discovery_ids":[1]},{"term_id":"R-HSA-109582","term_label":"Hemostasis","supporting_discovery_ids":[2]},{"term_id":"R-HSA-1500931","term_label":"Cell-Cell communication","supporting_discovery_ids":[0,3]}],"complexes":[],"partners":["MAGI-1","NHERF-1","VE-CADHERIN"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"Q96AP7","full_name":"Endothelial cell-selective adhesion molecule","aliases":[],"length_aa":390,"mass_kda":41.2,"function":"Can mediate aggregation most likely through a homophilic molecular interaction","subcellular_location":"Cell junction, adherens junction; Cell junction, tight junction; Cell membrane","url":"https://www.uniprot.org/uniprotkb/Q96AP7/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/ESAM","classification":"Not Classified","n_dependent_lines":0,"n_total_lines":1208,"dependency_fraction":0.0},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/ESAM","total_profiled":1310},"omim":[{"mim_id":"620371","title":"NEURODEVELOPMENTAL DISORDER WITH INTRACRANIAL HEMORRHAGE, SEIZURES, AND SPASTICITY; NEDIHSS","url":"https://www.omim.org/entry/620371"},{"mim_id":"614281","title":"ENDOTHELIAL CELL ADHESION MOLECULE; ESAM","url":"https://www.omim.org/entry/614281"},{"mim_id":"608351","title":"IMMUNOGLOBULIN SUPERFAMILY, MEMBER 11; IGSF11","url":"https://www.omim.org/entry/608351"},{"mim_id":"181500","title":"SCHIZOPHRENIA; SCZD","url":"https://www.omim.org/entry/181500"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Approved","locations":[{"location":"Cell Junctions","reliability":"Approved"},{"location":"Cytosol","reliability":"Additional"}],"tissue_specificity":"Low tissue specificity","tissue_distribution":"Detected in all","driving_tissues":[],"url":"https://www.proteinatlas.org/search/ESAM"},"hgnc":{"alias_symbol":["W117m"],"prev_symbol":[]},"alphafold":{"accession":"Q96AP7","domains":[{"cath_id":"2.60.40.10","chopping":"31-151","consensus_level":"high","plddt":90.6892,"start":31,"end":151},{"cath_id":"2.60.40.10","chopping":"158-240","consensus_level":"high","plddt":96.7254,"start":158,"end":240}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q96AP7","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q96AP7-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q96AP7-F1-predicted_aligned_error_v6.png","plddt_mean":77.56},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=ESAM","jax_strain_url":"https://www.jax.org/strain/search?query=ESAM"},"sequence":{"accession":"Q96AP7","fasta_url":"https://rest.uniprot.org/uniprotkb/Q96AP7.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q96AP7/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q96AP7"}},"corpus_meta":[{"pmid":"16818677","id":"PMC_16818677","title":"ESAM supports neutrophil extravasation, activation of Rho, and VEGF-induced vascular permeability.","date":"2006","source":"The Journal of experimental medicine","url":"https://pubmed.ncbi.nlm.nih.gov/16818677","citation_count":188,"is_preprint":false},{"pmid":"12851705","id":"PMC_12851705","title":"IGSF11 gene, frequently up-regulated in intestinal-type gastric cancer, encodes adhesion molecule homologous to CXADR, FLJ22415 and ESAM.","date":"2003","source":"International journal of oncology","url":"https://pubmed.ncbi.nlm.nih.gov/12851705","citation_count":88,"is_preprint":false},{"pmid":"15383320","id":"PMC_15383320","title":"Endothelial adhesion molecule ESAM binds directly to the multidomain adaptor MAGI-1 and recruits it to cell contacts.","date":"2004","source":"Experimental cell research","url":"https://pubmed.ncbi.nlm.nih.gov/15383320","citation_count":72,"is_preprint":false},{"pmid":"19096010","id":"PMC_19096010","title":"The endothelial antigen ESAM marks primitive hematopoietic progenitors throughout life in mice.","date":"2008","source":"Blood","url":"https://pubmed.ncbi.nlm.nih.gov/19096010","citation_count":69,"is_preprint":false},{"pmid":"19740102","id":"PMC_19740102","title":"Endothelial cell specific adhesion molecule (ESAM) localizes to platelet-platelet contacts and regulates thrombus formation in vivo.","date":"2009","source":"Journal of thrombosis and haemostasis : JTH","url":"https://pubmed.ncbi.nlm.nih.gov/19740102","citation_count":52,"is_preprint":false},{"pmid":"31826650","id":"PMC_31826650","title":"Interference With ESAM (Endothelial Cell-Selective Adhesion Molecule) Plus Vascular Endothelial-Cadherin Causes Immediate Lethality and Lung-Specific Blood Coagulation.","date":"2019","source":"Arteriosclerosis, thrombosis, and vascular biology","url":"https://pubmed.ncbi.nlm.nih.gov/31826650","citation_count":36,"is_preprint":false},{"pmid":"24204843","id":"PMC_24204843","title":"Transcriptional reprogramming of CD11b+Esam(hi) dendritic cell identity and function by loss of Runx3.","date":"2013","source":"PloS one","url":"https://pubmed.ncbi.nlm.nih.gov/24204843","citation_count":30,"is_preprint":false},{"pmid":"22649198","id":"PMC_22649198","title":"The endothelial antigen ESAM monitors hematopoietic stem cell status between quiescence and self-renewal.","date":"2012","source":"Journal of immunology (Baltimore, Md. : 1950)","url":"https://pubmed.ncbi.nlm.nih.gov/22649198","citation_count":28,"is_preprint":false},{"pmid":"32637582","id":"PMC_32637582","title":"miR-7 Reduces Breast Cancer Stem Cell Metastasis via Inhibiting RELA to Decrease ESAM Expression.","date":"2020","source":"Molecular therapy oncolytics","url":"https://pubmed.ncbi.nlm.nih.gov/32637582","citation_count":27,"is_preprint":false},{"pmid":"26774386","id":"PMC_26774386","title":"ESAM is a novel human hematopoietic stem cell marker associated with a subset of human leukemias.","date":"2016","source":"Experimental hematology","url":"https://pubmed.ncbi.nlm.nih.gov/26774386","citation_count":21,"is_preprint":false},{"pmid":"36996813","id":"PMC_36996813","title":"Bi-allelic variants in the ESAM tight-junction gene cause a neurodevelopmental disorder associated with fetal intracranial hemorrhage.","date":"2023","source":"American journal of human genetics","url":"https://pubmed.ncbi.nlm.nih.gov/36996813","citation_count":15,"is_preprint":false},{"pmid":"28630070","id":"PMC_28630070","title":"Regulation of Type III Secretion of Translocon and Effector Proteins by the EsaB/EsaL/EsaM Complex in Edwardsiella tarda.","date":"2017","source":"Infection and immunity","url":"https://pubmed.ncbi.nlm.nih.gov/28630070","citation_count":14,"is_preprint":false},{"pmid":"35357005","id":"PMC_35357005","title":"Flt3L, LIF, and IL-10 combination promotes the selective in vitro development of ESAMlow cDC2B from murine bone marrow.","date":"2022","source":"European journal of immunology","url":"https://pubmed.ncbi.nlm.nih.gov/35357005","citation_count":7,"is_preprint":false},{"pmid":"35457187","id":"PMC_35457187","title":"3D Visualization of Human Blood Vascular Networks Using Single-Domain Antibodies Directed against Endothelial Cell-Selective Adhesion Molecule (ESAM).","date":"2022","source":"International journal of molecular sciences","url":"https://pubmed.ncbi.nlm.nih.gov/35457187","citation_count":3,"is_preprint":false},{"pmid":"39414991","id":"PMC_39414991","title":"Novel homozygous ESAM variants in two families with perinatal strokes showing variable neuroradiologic and clinical findings.","date":"2024","source":"Journal of human genetics","url":"https://pubmed.ncbi.nlm.nih.gov/39414991","citation_count":3,"is_preprint":false},{"pmid":"26329529","id":"PMC_26329529","title":"ESAM predicts cardiovascular mortality in diabetic hemodialysis patients.","date":"2015","source":"Biomarkers : biochemical indicators of exposure, response, and susceptibility to chemicals","url":"https://pubmed.ncbi.nlm.nih.gov/26329529","citation_count":0,"is_preprint":false},{"pmid":"36058862","id":"PMC_36058862","title":"[Exploring new molecules that regulate hematopoietic stem cells and early stages of lymphoid hematopoiesis: the functional significance of ESAM and SATB1].","date":"2022","source":"[Rinsho ketsueki] The Japanese journal of clinical hematology","url":"https://pubmed.ncbi.nlm.nih.gov/36058862","citation_count":0,"is_preprint":false},{"pmid":"38008937","id":"PMC_38008937","title":"Extraretinal Fibrovascular Proliferation in a Neonate Possibly Associated with an ESAM Gene Variant.","date":"2023","source":"Turkish journal of ophthalmology","url":"https://pubmed.ncbi.nlm.nih.gov/38008937","citation_count":0,"is_preprint":false},{"pmid":"41525715","id":"PMC_41525715","title":"ESAM Loss of Function and Congenital Neurovascular Injury: Strengthening the Case for a Recognizable Clinical Phenotype.","date":"2026","source":"Clinical genetics","url":"https://pubmed.ncbi.nlm.nih.gov/41525715","citation_count":0,"is_preprint":false},{"pmid":"26062667","id":"PMC_26062667","title":"[Role of endothelial antigen ESAM in activated hematopoietic stem cells].","date":"2015","source":"[Rinsho ketsueki] The Japanese journal of clinical hematology","url":"https://pubmed.ncbi.nlm.nih.gov/26062667","citation_count":0,"is_preprint":false},{"pmid":null,"id":"bio_10.1101_2025.10.19.683343","title":"Transcriptomic profiling of the middle temporal gyrus reveals differential glial/neuronal dysregulation across Alzheimer’s disease and aging","date":"2025-10-20","source":"bioRxiv","url":"https://doi.org/10.1101/2025.10.19.683343","citation_count":0,"is_preprint":true},{"pmid":null,"id":"bio_10.1101_2025.02.15.638465","title":"Single Cell Proteomics Reveals Novel Cell Phenotypes in Marfan Mouse Aneurysm","date":"2025-02-23","source":"bioRxiv","url":"https://doi.org/10.1101/2025.02.15.638465","citation_count":0,"is_preprint":true}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":13933,"output_tokens":2171,"usd":0.037182,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":9225,"output_tokens":2564,"usd":0.055113,"stage2_stop_reason":"end_turn"},"total_usd":0.092295,"stage1_batch_id":"msgbatch_01AsR7g8dGTEiEw9U83bJeWn","stage2_batch_id":"msgbatch_01YV5ZyxtFNUZEjxRcpd9jzb","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2004,\n      \"finding\": \"ESAM directly binds the multidomain adaptor protein MAGI-1 via a PDZ domain-mediated interaction at its C-terminal sequence. This interaction was confirmed by yeast two-hybrid screen, pull-down experiments, and co-immunoisolation from transfected CHO cells. ESAM recruits MAGI-1 to cell-cell contacts; in CHO cells, MAGI-1 localization to cell contacts required the presence of ESAM.\",\n      \"method\": \"Yeast two-hybrid screen, pull-down assay, co-immunoprecipitation from transfected CHO cells, colocalization in HUVECs and mouse endothelium\",\n      \"journal\": \"Experimental cell research\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — reciprocal binding confirmed by multiple orthogonal methods (yeast two-hybrid, pulldown, Co-IP, localization rescue) in a single focused study\",\n      \"pmids\": [\"15383320\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2006,\n      \"finding\": \"ESAM at endothelial tight junctions supports neutrophil extravasation: ESAM-/- mice showed ~50% reduction in leukocyte extravasation in cremaster muscle by intravital microscopy without affecting rolling/adhesion, and ~70% reduction in neutrophil migration into inflamed peritoneum at 2 h. Platelet depletion did not abolish this effect, indicating endothelial ESAM is the relevant pool. Knockdown of ESAM in endothelial cells reduced activated Rho GTPase levels. VEGF-induced vascular permeability was also reduced in ESAM-/- mice.\",\n      \"method\": \"ESAM knockout mouse model, intravital microscopy, peritonitis inflammation model, siRNA knockdown in endothelial cells, Rho activation assay, VEGF permeability assay\",\n      \"journal\": \"The Journal of experimental medicine\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — clean KO with multiple defined phenotypic readouts (intravital microscopy, permeability assay), platelet depletion epistasis, and Rho activity measurement in a single rigorous study\",\n      \"pmids\": [\"16818677\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2009,\n      \"finding\": \"Following platelet activation, ESAM localizes to junctions between adjacent platelets. ESAM-/- mice formed larger thrombi and achieved more stable hemostasis than wild-type mice. ESAM-/- platelets aggregated at lower agonist concentrations and were more resistant to disaggregation, while calcium mobilization, αIIbβ3 activation, alpha-granule secretion, and platelet spreading were normal. Using a PDZ domain array, the scaffold protein NHERF-1 was identified as an ESAM binding partner, associating with ESAM in both resting and activated platelets.\",\n      \"method\": \"ESAM knockout mouse model, laser injury thrombosis model, tail transection hemostasis assay, in vitro platelet aggregation, PDZ domain array, co-immunoprecipitation\",\n      \"journal\": \"Journal of thrombosis and haemostasis : JTH\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — KO with multiple functional phenotypic readouts (in vivo thrombosis, in vitro aggregation), PDZ array plus Co-IP for binding partner identification, single lab with multiple orthogonal methods\",\n      \"pmids\": [\"19740102\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"ESAM is required for endothelial barrier integrity specifically in the lung; ESAM gene inactivation enhanced vascular permeability in lung but not heart, skin, or brain. Combined loss of ESAM and VE-cadherin (by antibody blockade or induced gene inactivation) caused immediate lethality within 30 minutes, disrupted endothelial junctions ultrastructurally, and caused massive blood coagulation in the lung — effects not seen with loss of JAM-A or PECAM-1 combined with VE-cadherin blockade. Mechanistically, platelet ESAM was excluded as the relevant pool, and cytoplasmic signaling domains of ESAM were found not to contribute to this phenotype.\",\n      \"method\": \"Inducible gene knockout mouse models, antibody blocking in vivo, vascular permeability assays, electron microscopy ultrastructural analysis, genetic epistasis (double KO)\",\n      \"journal\": \"Arteriosclerosis, thrombosis, and vascular biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — genetic epistasis with multiple KO combinations, ultrastructural validation, tissue-specific permeability assays, negative controls (JAM-A, PECAM-1) in a single rigorous study\",\n      \"pmids\": [\"31826650\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"ESAM expression levels on HSCs mirror the shift between quiescence and active proliferation/self-renewal. ESAMhi HSCs are actively dividing yet retain high long-term reconstituting capacity. ESAM-/- mice showed severe and prolonged bone marrow suppression after 5-fluorouracil treatment, indicating ESAM is functionally indispensable for HSC-mediated re-establishment of homeostatic hematopoiesis. ESAMhi HSCs were located near vascular endothelium after BM injury. NF-κB and topoisomerase II levels correlated with ESAM upregulation.\",\n      \"method\": \"ESAM knockout mouse model, 5-FU bone marrow injury model, cell cycle analysis, long-term reconstitution transplantation assay, immunohistochemistry\",\n      \"journal\": \"Journal of immunology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — clean KO with defined hematopoietic reconstitution phenotype and cell-cycle readout, single lab\",\n      \"pmids\": [\"22649198\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"Bi-allelic loss-of-function variants in ESAM cause defective in vitro tubulogenesis of endothelial colony-forming cells, recapitulating the vascular phenotype seen in null mice, and result in absence of ESAM expression in capillary endothelial cells of damaged brain. This establishes ESAM as a tight junction molecule essential for brain vascular integrity.\",\n      \"method\": \"Human genetics (exome sequencing), in vitro tubulogenesis assay of patient-derived endothelial colony-forming cells, immunostaining of patient brain tissue\",\n      \"journal\": \"American journal of human genetics\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — functional in vitro assay with patient-derived cells plus tissue immunostaining, single study with orthogonal approaches\",\n      \"pmids\": [\"36996813\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2009,\n      \"finding\": \"In resting platelets, ESAM is stored in alpha granules and translocates to the platelet surface following platelet activation, localizing specifically to platelet-platelet contact junctions.\",\n      \"method\": \"Immunofluorescence localization in activated vs. resting platelets\",\n      \"journal\": \"Journal of thrombosis and haemostasis : JTH\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 / Moderate — direct localization experiment with functional context, single lab, imaging-based\",\n      \"pmids\": [\"19740102\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"ESAM is an immunoglobulin-superfamily transmembrane protein localized at endothelial tight junctions and platelet alpha granules (translocating to platelet-platelet contacts upon activation) that maintains vascular barrier integrity — particularly in the lung in cooperation with VE-cadherin — supports neutrophil extravasation by activating Rho GTPase at endothelial junctions, limits thrombus growth via NHERF-1 scaffold interactions at platelet contacts, and anchors the adaptor protein MAGI-1 at endothelial cell contacts through a C-terminal PDZ domain interaction; it is also functionally required for hematopoietic stem cell-mediated reconstitution of homeostatic hematopoiesis after bone marrow injury.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"ESAM is an immunoglobulin-superfamily adhesion molecule that operates at endothelial junctions and at platelet contacts to regulate vascular barrier integrity, inflammatory cell trafficking, and thrombus stability [#1, #3]. At endothelial tight junctions ESAM anchors the multidomain scaffold MAGI-1 through a C-terminal PDZ-mediated interaction, and ESAM is required to recruit MAGI-1 to cell-cell contacts [#0]. Endothelial ESAM supports neutrophil extravasation downstream of an activated Rho GTPase signal at the junction \\u2014 acting on the diapedesis step rather than rolling or adhesion \\u2014 and contributes to VEGF-induced vascular permeability [#1]. ESAM maintains barrier integrity in a tissue-restricted manner, with permeability defects in the lung; combined loss of ESAM and VE-cadherin causes ultrastructural junction disruption, pulmonary coagulation, and rapid lethality, defining a cooperative role with VE-cadherin not shared by JAM-A or PECAM-1 [#3]. In platelets, ESAM is stored in alpha granules and translocates to platelet-platelet contact junctions upon activation, where it binds the scaffold NHERF-1 and limits thrombus growth and stability without altering calcium mobilization, integrin activation, or granule secretion [#2, #6]. ESAM is also functionally indispensable for hematopoietic stem cell-mediated re-establishment of homeostatic hematopoiesis after bone marrow injury [#4]. Bi-allelic loss-of-function variants in ESAM impair endothelial tubulogenesis and cause defective brain vascular integrity in humans [#5].\",\n  \"teleology\": [\n    {\n      \"year\": 2004,\n      \"claim\": \"Established the first molecular partner of ESAM, showing how an endothelial junctional protein could organize an intracellular scaffold at cell contacts.\",\n      \"evidence\": \"Yeast two-hybrid, pull-down, and Co-IP in transfected CHO cells with colocalization in HUVECs and mouse endothelium\",\n      \"pmids\": [\"15383320\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Does not define the downstream signaling consequence of MAGI-1 recruitment\", \"Functional role of the ESAM-MAGI-1 complex in vivo not tested\"]\n    },\n    {\n      \"year\": 2006,\n      \"claim\": \"Resolved which step of leukocyte trafficking ESAM controls and linked endothelial ESAM to Rho GTPase activation, distinguishing diapedesis from adhesion.\",\n      \"evidence\": \"ESAM-/- mice, intravital microscopy, peritonitis model, endothelial siRNA knockdown, Rho activation assay, and VEGF permeability assay\",\n      \"pmids\": [\"16818677\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Mechanism connecting ESAM to Rho activation not defined\", \"Whether MAGI-1 mediates the Rho effect untested\"]\n    },\n    {\n      \"year\": 2009,\n      \"claim\": \"Defined a platelet-intrinsic role for ESAM in limiting thrombus growth and identified its platelet scaffold partner, separating it from the general platelet activation machinery.\",\n      \"evidence\": \"ESAM-/- mice, laser injury thrombosis and tail transection assays, in vitro aggregation, PDZ domain array, and Co-IP; immunofluorescence of resting vs activated platelets\",\n      \"pmids\": [\"19740102\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Mechanism by which NHERF-1 binding restrains aggregation not resolved\", \"Signaling output of ESAM at platelet contacts unknown\"]\n    },\n    {\n      \"year\": 2012,\n      \"claim\": \"Connected ESAM expression to HSC proliferative state and demonstrated it is functionally required for regenerative hematopoiesis after injury.\",\n      \"evidence\": \"ESAM-/- mice, 5-FU bone marrow injury, cell-cycle analysis, long-term reconstitution transplantation, and immunohistochemistry\",\n      \"pmids\": [\"22649198\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Molecular mechanism of ESAM in HSC self-renewal not defined\", \"Relationship between NF-kB/topoisomerase II correlation and ESAM function unestablished\"]\n    },\n    {\n      \"year\": 2019,\n      \"claim\": \"Showed ESAM cooperates with VE-cadherin for barrier integrity in a tissue-specific (lung) manner, and that its cytoplasmic signaling domains are dispensable for this phenotype.\",\n      \"evidence\": \"Inducible KO mice, in vivo antibody blockade, tissue-specific permeability assays, electron microscopy, and genetic epistasis with VE-cadherin, JAM-A, and PECAM-1\",\n      \"pmids\": [\"31826650\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Molecular basis of ESAM/VE-cadherin cooperation unresolved\", \"Why the phenotype is lung-restricted not explained\"]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"Provided human genetic evidence that ESAM loss of function causes defective endothelial tubulogenesis and brain vascular pathology, translating mouse phenotypes to disease.\",\n      \"evidence\": \"Exome sequencing, in vitro tubulogenesis of patient endothelial colony-forming cells, and patient brain immunostaining\",\n      \"pmids\": [\"36996813\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Mechanism linking ESAM loss to tubulogenesis failure not defined\", \"Genotype-phenotype correlation across patients limited\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How ESAM's junctional scaffold interactions (MAGI-1, NHERF-1) mechanistically couple to Rho GTPase signaling, VE-cadherin cooperation, and HSC regeneration remains unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No structural model of ESAM-scaffold complexes\", \"Signaling pathway downstream of ESAM at junctions not mapped\", \"Tissue specificity of barrier function unexplained\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0098631\", \"supporting_discovery_ids\": [1, 2, 3]},\n      {\"term_id\": \"GO:0060090\", \"supporting_discovery_ids\": [0, 2]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005886\", \"supporting_discovery_ids\": [1, 3, 6]},\n      {\"term_id\": \"GO:0031410\", \"supporting_discovery_ids\": [6]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-168256\", \"supporting_discovery_ids\": [1]},\n      {\"term_id\": \"R-HSA-109582\", \"supporting_discovery_ids\": [2]},\n      {\"term_id\": \"R-HSA-1500931\", \"supporting_discovery_ids\": [0, 3]}\n    ],\n    \"complexes\": [],\n    \"partners\": [\"MAGI-1\", \"NHERF-1\", \"VE-cadherin\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":6,"faith_total":7,"faith_pct":85.71428571428571}}