{"gene":"ADGRE2","run_date":"2026-04-28T17:12:37","timeline":{"discoveries":[{"year":2000,"finding":"EMR2 (ADGRE2) is a member of the EGF-TM7 family of class B GPCRs, containing N-terminal EGF-like domains coupled to a seven-span transmembrane domain via a mucin-like spacer. Expression is restricted to monocytes/macrophages and granulocytes, and unlike CD97 it does not interact with CD55, indicating distinct ligand specificity.","method":"Genomic mapping, alternative splicing analysis, monoclonal antibody binding assays, flow cytometry on primary leukocytes","journal":"Genomics","confidence":"High","confidence_rationale":"Tier 2 — foundational characterization with multiple orthogonal methods, highly cited","pmids":["10903844"],"is_preprint":false},{"year":2002,"finding":"EMR2 is expressed as a heterodimeric receptor consisting of an extracellular alpha subunit and a seven-transmembrane/cytoplasmic beta subunit, with myeloid-restricted expression (highest on CD16+ monocytes, macrophages, and BDCA-3+ myeloid DCs).","method":"Monoclonal antibody generation (2A1), immunoprecipitation, flow cytometry on primary blood leukocytes and hematopoietic cell lines, in situ analysis","journal":"Journal of leukocyte biology","confidence":"High","confidence_rationale":"Tier 2 — reciprocal antibody-based detection and fractionation with multiple cell types, replicated across labs","pmids":["11994511"],"is_preprint":false},{"year":2003,"finding":"The EGF-like domains of EMR2 mediate cell attachment through chondroitin sulfate (CS) glycosaminoglycans; the fourth EGF-like module constitutes the major ligand-binding site, and the interaction is Ca2+- and sulphation-dependent.","method":"Multivalent protein probes, antibody-blocking studies, mutant CHO cell lines defective in GAG biosynthesis, enzymatic removal of cell surface GAGs, dose-dependent competition with exogenous CS","journal":"Blood","confidence":"High","confidence_rationale":"Tier 1 — reconstituted ligand interaction with genetic (mutant CHO) and enzymatic validation, highly cited","pmids":["12829604"],"is_preprint":false},{"year":2003,"finding":"Proteolytic cleavage of EMR2 occurs at Leu517-Ser518 within the GPS motif, is independent of transmembrane domains, requires the entire extracellular stalk (not GPS alone), and the non-covalent alpha-beta subunit association requires a minimum of eight amino acids in the beta-subunit. An alternatively spliced isoform with truncated stalk fails to undergo cleavage.","method":"Site-directed mutagenesis, cell-free cleavage assays, analysis of alternatively spliced isoforms, biochemical fractionation","journal":"FEBS letters","confidence":"High","confidence_rationale":"Tier 1 — in vitro mutagenesis and cell-free reconstitution defining exact cleavage site and requirements","pmids":["12860403"],"is_preprint":false},{"year":2004,"finding":"GPS autoproteolysis of EMR2 is an autocatalytic intramolecular reaction at His-Leu↓Ser518; requires Ser, Thr, or Cys at P(+1) and His at P(-2) for efficient cleavage; occurs in the ER; produces two subunits that associate noncovalently. The mechanism resembles N-terminal nucleophile hydrolases performing cis-proteolysis.","method":"Site-directed mutagenesis of GPS residues, cell-free system spontaneous hydrolysis assay, biochemical characterization of ER localization of cleavage","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1 — in vitro reconstitution with mutagenesis defining catalytic mechanism, highly cited","pmids":["15150276"],"is_preprint":false},{"year":2004,"finding":"The fourth EGF domain of EMR2 (present on activated lymphocytes and myeloid cells) binds chondroitin sulfate specifically on B cells within peripheral blood, suggesting a role in T cell/DC/macrophage interactions with B cells.","method":"Fluorescent beads coated with recombinant CD97 and EMR2, isoform-specific monoclonal antibodies, flow cytometry on peripheral blood leukocytes","journal":"Journal of leukocyte biology","confidence":"Medium","confidence_rationale":"Tier 2 — direct binding assay with isoform-specific antibodies, single lab","pmids":["15498814"],"is_preprint":false},{"year":2005,"finding":"In rheumatoid synovial tissue, dermatan sulfate is the endogenous ligand for the largest isoforms of EMR2 and CD97. EMR2 is expressed on macrophages and dendritic cells expressing costimulatory molecules and TNFα in synovium.","method":"Immunohistochemistry, double immunofluorescence, EMR2/CD97-specific multivalent fluorescent probe binding assays on synovial tissue sections","journal":"Arthritis and rheumatism","confidence":"Medium","confidence_rationale":"Tier 2 — direct tissue binding assay with specific probes identifying endogenous ligand in vivo","pmids":["15693006"],"is_preprint":false},{"year":2006,"finding":"EMR2 expression is up-regulated during macrophage differentiation/maturation and down-regulated during dendritic cell maturation; LPS and IL-10 (via an IL-10-mediated pathway) specifically up-regulate EMR2 in monocytes and macrophages. Alternative splicing and glycosylation of EMR2 are regulated during myeloid differentiation.","method":"Flow cytometry, ELISA, immunohistochemistry, specific mAb-based detection of isoforms, siRNA/inhibitor dissection of LPS/IL-10 pathways","journal":"Biochemical and biophysical research communications","confidence":"Medium","confidence_rationale":"Tier 2 — multiple methods in single lab defining regulatory pathway","pmids":["17174274"],"is_preprint":false},{"year":2007,"finding":"Ligation of EMR2 on neutrophils increases adhesion, migration, superoxide production, and proteolytic enzyme degranulation by potentiating proinflammatory mediator effects; upon activation EMR2 translocates to membrane ruffles and the leading edge; the transmembrane region is critical for these signaling functions.","method":"Anti-EMR2 antibody ligation, superoxide assay, degranulation assay, live-cell imaging showing translocation to membrane ruffles, dominant-negative transmembrane domain constructs","journal":"FASEB journal","confidence":"High","confidence_rationale":"Tier 2 — multiple functional readouts with mechanistic dissection of transmembrane domain requirement, replicated across multiple proinflammatory stimuli","pmids":["17928360"],"is_preprint":false},{"year":2012,"finding":"GPS autoproteolysis produces two distinct EMR2 receptor complexes: a noncovalent alpha-beta heterodimer and two completely independent subunits that distribute differentially in lipid raft microdomains. Receptor ligation induces subunit translocation and colocalization within lipid rafts, leading to signaling and inflammatory cytokine production by macrophages.","method":"Biochemical fractionation of lipid rafts, co-immunoprecipitation, antibody-mediated ligation, cytokine ELISA, GPS mutant constructs","journal":"Molecular and cellular biology","confidence":"High","confidence_rationale":"Tier 1–2 — GPS mutagenesis combined with lipid raft fractionation and functional cytokine readout, mechanistically resolves subunit distribution","pmids":["22310662"],"is_preprint":false},{"year":2016,"finding":"A missense variant p.C492Y in ADGRE2 causes familial vibratory urticaria by destabilizing the autoinhibitory noncovalent subunit interaction between the extracellular and transmembrane subunits, sensitizing mast cells to IgE-independent vibration-induced degranulation.","method":"Human genetics (variant co-segregation in two kindreds), biochemical subunit interaction assays, mast cell degranulation assays with vibration stimulation","journal":"The New England journal of medicine","confidence":"High","confidence_rationale":"Tier 2 — co-segregation genetics plus biochemical subunit destabilization assay and functional mast cell degranulation, highly cited","pmids":["26841242"],"is_preprint":false},{"year":2017,"finding":"Activation of EMR2 via agonistic antibody promotes THP-1 monocyte differentiation and induces IL-8, TNF-α, and MMP-9 expression through a Gα16-initiated signaling cascade activating Akt, ERK, JNK, and NF-κB.","method":"Anti-EMR2 antibody ligation, specific signaling inhibitors, siRNA knockdowns of pathway components, ELISA for cytokines, flow cytometry for differentiation markers","journal":"Frontiers in immunology","confidence":"High","confidence_rationale":"Tier 2 — siRNA knockdown of specific G protein combined with inhibitor dissection and multiple functional readouts","pmids":["28421075"],"is_preprint":false},{"year":2018,"finding":"The membrane-associated NTF (N-terminal fragment) of EMR2 is regulated by site-specific N-glycosylation in the GAIN domain occurring in post-ER compartments; a unique amphipathic alpha-helix in the GAIN domain serves as a putative membrane anchor of the NTF, independent of the CTF.","method":"Glycosylation site mutagenesis, subcellular fractionation, glycosidase treatment, confocal imaging of compartment-specific localization","journal":"Scientific reports","confidence":"Medium","confidence_rationale":"Tier 1–2 — mutagenesis of glycosylation sites combined with fractionation, single lab","pmids":["29540735"],"is_preprint":false},{"year":2020,"finding":"ADGRE2/EMR2 couples broadly to G proteins (Gα16, Gα12, Gα13, Gα14, Gαz, Gα16/Gαz chimera) as shown by activated truncated receptor forms; EMR2 signals via Gα16 to stimulate IP1 accumulation and induces pertussis-toxin-insensitive inhibition of cAMP, suggesting Gαz coupling. An anti-EMR2 polyclonal antibody activates G protein signaling in vitro.","method":"Yeast-based G protein coupling assay with chimeric G proteins, mammalian cAMP assay with pertussis toxin, IP1 accumulation assay, NFAT reporter assay","journal":"Scientific reports","confidence":"High","confidence_rationale":"Tier 1–2 — multiple recombinant systems and pharmacological dissection across multiple G protein subtypes","pmids":["31969668"],"is_preprint":false},{"year":2020,"finding":"Mechanical activation (vibration) of mast cells expressing p.C492Y-ADGRE2 attached to dermatan sulfate activates phospholipase C, causing transient cytosolic Ca2+ increase and downstream activation of PI3K and ERK1/2 via Gβγ, Gαq/11, and Gαi/o-independent mechanisms; degranulation requires PLC/Ca2+/PKC/PI3K pathways plus pertussis toxin-sensitive signals; prostaglandin D2 synthesis requires ERK1/2, Ca2+, PKC, and PI3K.","method":"Vibration stimulation of primary human mast cells, Ca2+ imaging, pharmacological inhibitors of PLC/PI3K/PKC/ERK, pertussis toxin treatment, degranulation assay, prostaglandin D2 ELISA","journal":"The Journal of investigative dermatology","confidence":"High","confidence_rationale":"Tier 2 — pharmacological dissection with multiple inhibitors in primary human mast cells with multiple functional readouts","pmids":["32222457"],"is_preprint":false},{"year":2021,"finding":"EMR2 activation by agonistic antibody triggers the NLRP3 inflammasome activation (2nd) signal in THP-1 monocytes and primary monocytes via Gα16-dependent PLC-β activation, leading to Akt, MAPK, NF-κB activity, Ca2+ mobilization, and K+ efflux.","method":"Anti-EMR2 mAb ligation, siRNA knockdown of Gα16 and PLC-β, K+ efflux measurement, NLRP3 inflammasome activation assays, pharmacological inhibitors","journal":"Frontiers in immunology","confidence":"High","confidence_rationale":"Tier 2 — siRNA knockdown of specific G protein subunit combined with multiple downstream pathway readouts","pmids":["33488598"],"is_preprint":false},{"year":2024,"finding":"ADGRE2 activates a PLCβ/PKC/MEK/ERK signaling cascade that drives AP1 transcriptional activity, which in turn transcriptionally upregulates DUSP1; DUSP1 dephosphorylates Ser16 of the co-chaperone DNAJB1 to facilitate DNAJB1-HSP70 interaction and maintain proteostasis in AML leukemic stem cells.","method":"ADGRE2 silencing in AML cell lines and patient-derived cells, xenograft mouse models, ChIP-seq/RNA-seq for AP1 targets, DUSP1 phosphorylation assays, co-immunoprecipitation of DNAJB1-HSP70, combined MEK/AP1/DUSP1 inhibitor treatment","journal":"Cancer research","confidence":"High","confidence_rationale":"Tier 2 — multiple orthogonal methods including KO, in vivo xenograft, co-IP, and phosphorylation assays in a single study","pmids":["39082681"],"is_preprint":false},{"year":2024,"finding":"CD312/ADGRE2 interacts with GNA15 (Gα15) at the transmembrane intracellular segment, and this interaction promotes leukaemia cell proliferation via phosphorylation of ERK, JNK, and p38 in a co-culture system; GNA15 knockdown abrogates this proliferative effect.","method":"Co-immunoprecipitation (GNA15-CD312 interaction), BrdU proliferation assay, GNA15 siRNA knockdown, phospho-Western blotting for ERK/JNK/p38","journal":"Journal of cellular and molecular medicine","confidence":"Medium","confidence_rationale":"Tier 2–3 — Co-IP plus functional siRNA knockdown, single lab","pmids":["39656442"],"is_preprint":false},{"year":2019,"finding":"EMR2 contains an SGD sequence (corresponding to RGD in CD97) that prevents integrin α5β1 binding and angiogenesis induction; substituting SGD→RGD in EMR2 enables it to upregulate MMP-9 and induce angiogenesis via N-cadherin-regulated MMP-9 expression, similar to CD97.","method":"Site-directed mutagenesis of RGD/SGD motif, in vitro endothelial tube formation assay, in ovo chick CAM assay, MMP-9 expression analysis, N-cadherin modulation experiments","journal":"Biochemical and biophysical research communications","confidence":"Medium","confidence_rationale":"Tier 1–2 — mutagenesis with in vitro and in vivo angiogenesis functional readouts, single lab","pmids":["31594642"],"is_preprint":false}],"current_model":"ADGRE2/EMR2 is a myeloid-restricted adhesion GPCR that undergoes autocatalytic GPS/GAIN-domain cis-proteolysis in the ER to generate noncovalently associated extracellular (NTF) and seven-transmembrane (CTF) subunits; the NTF binds chondroitin/dermatan sulfate glycosaminoglycans via its fourth EGF-like domain, and mechanical or antibody-mediated receptor ligation induces lipid-raft translocation and Gα16/Gαz-coupled signaling through PLC-β, Akt, MAPK, and NF-κB to drive neutrophil and macrophage activation, mast cell degranulation (sensitized by the disease-causing p.C492Y variant that destabilizes subunit interaction), NLRP3 inflammasome priming, and in AML a PLCβ/PKC/MEK/ERK/AP1/DUSP1 axis that sustains proteostasis in leukemic stem cells."},"narrative":{"teleology":[{"year":2000,"claim":"Identification of EMR2 as a novel EGF-TM7 family GPCR with myeloid-restricted expression established the receptor as distinct from the related CD97 and defined its lineage specificity.","evidence":"Genomic cloning, splice analysis, mAb binding, and flow cytometry on primary leukocytes","pmids":["10903844"],"confidence":"High","gaps":["No ligand identified","No signaling mechanism defined","Functional role in myeloid cells unknown"]},{"year":2002,"claim":"Demonstration that EMR2 exists as a heterodimeric receptor with an extracellular α-subunit and a TM β-subunit resolved its biochemical architecture and refined its expression to CD16+ monocytes and myeloid DCs.","evidence":"Monoclonal antibody immunoprecipitation and flow cytometry across primary blood cell populations","pmids":["11994511"],"confidence":"High","gaps":["Mechanism of heterodimer formation unknown","Subunit stoichiometry not addressed"]},{"year":2003,"claim":"Identification of chondroitin sulfate GAGs as the ligand for the fourth EGF-like domain and mapping of the GPS cleavage site to Leu517↓Ser518 established the receptor's extracellular recognition mechanism and its autoproteolytic processing requirements.","evidence":"Multivalent probes on mutant CHO cells defective in GAG synthesis; site-directed mutagenesis and cell-free cleavage assays","pmids":["12829604","12860403"],"confidence":"High","gaps":["Whether GPS cleavage is required for signaling not tested","In vivo GAG ligand identity unconfirmed"]},{"year":2004,"claim":"Establishing that GPS cleavage is an autocatalytic intramolecular cis-proteolysis occurring in the ER with N-terminal nucleophile hydrolase-like chemistry defined the biogenesis mechanism of the two-subunit receptor.","evidence":"Site-directed mutagenesis of catalytic residues (His, Ser518), cell-free spontaneous hydrolysis, ER localization analysis","pmids":["15150276"],"confidence":"High","gaps":["Structural basis of autocatalysis not resolved at atomic level","Whether all splice isoforms are equally processed unclear"]},{"year":2006,"claim":"Showing that EMR2 expression is dynamically regulated during myeloid differentiation—up by LPS and IL-10 in macrophages, down during DC maturation—placed the receptor within innate immune activation programs.","evidence":"Flow cytometry, ELISA, mAb isoform detection, and siRNA/inhibitor dissection of LPS/IL-10 signaling in primary monocytes and macrophages","pmids":["17174274"],"confidence":"Medium","gaps":["Transcription factors controlling ADGRE2 expression not identified","Functional consequence of isoform switching not tested"]},{"year":2007,"claim":"Demonstrating that EMR2 ligation on neutrophils enhances adhesion, migration, superoxide production, and degranulation—with requirement for the transmembrane domain—established the receptor as a functional activator of innate effector responses.","evidence":"Anti-EMR2 antibody ligation with superoxide/degranulation assays, live-cell imaging of translocation to membrane ruffles, dominant-negative TM constructs","pmids":["17928360"],"confidence":"High","gaps":["Downstream G protein identity not determined","Physiological ligand triggering in vivo not shown"]},{"year":2012,"claim":"Resolution of two distinct post-cleavage receptor complexes—noncovalent heterodimer and independent subunits—and their differential lipid-raft distribution revealed that ligation-induced raft coalescence is the proximal signaling event driving macrophage cytokine production.","evidence":"Lipid raft fractionation, co-immunoprecipitation, GPS mutant constructs, and cytokine ELISA after antibody ligation","pmids":["22310662"],"confidence":"High","gaps":["How raft translocation activates specific G proteins unresolved","Relative contribution of heterodimer vs. independent subunits to signaling unclear"]},{"year":2016,"claim":"Discovery that p.C492Y destabilizes NTF–CTF interaction and causes familial vibratory urticaria linked mechanical force sensing to subunit dissociation as the activation mechanism and established the first Mendelian disease for an adhesion GPCR.","evidence":"Co-segregation in two kindreds, biochemical subunit interaction assays, vibration-induced mast cell degranulation","pmids":["26841242"],"confidence":"High","gaps":["Structural consequence of C492Y at atomic resolution unknown","Whether other destabilizing variants cause related phenotypes untested"]},{"year":2017,"claim":"Identification of Gα16 as the coupling partner initiating a PLC-β/Akt/ERK/JNK/NF-κB signaling cascade upon EMR2 activation resolved the G protein identity and downstream pathway architecture in monocytes.","evidence":"siRNA knockdown of Gα16, specific inhibitors of PLC-β/Akt/ERK/JNK/NF-κB, ELISA for IL-8/TNF-α/MMP-9 in THP-1 cells","pmids":["28421075"],"confidence":"High","gaps":["Whether Gα16 is the sole coupling partner in all myeloid lineages unclear","Direct Gα16–receptor interaction not shown biochemically"]},{"year":2020,"claim":"Comprehensive G protein coupling profiling revealed broad coupling to Gα16, Gα12/13, Gα14, and Gαz, while pharmacological dissection of vibration-stimulated mast cells mapped degranulation to PLC/Ca²⁺/PKC/PI3K plus pertussis-toxin-sensitive signals, defining the full signaling repertoire.","evidence":"Yeast chimeric G protein coupling assay, mammalian cAMP/IP1 assays, Ca²⁺ imaging and pharmacological inhibitor panel in primary mast cells","pmids":["31969668","32222457"],"confidence":"High","gaps":["Gβγ subunit composition not identified","Whether mechanical vs. ligand-mediated activation engages identical G protein sets untested"]},{"year":2021,"claim":"Showing that EMR2 provides the second activation signal for NLRP3 inflammasome assembly via Gα16–PLCβ–dependent K⁺ efflux and Ca²⁺ mobilization extended the receptor's role to inflammasome biology.","evidence":"Anti-EMR2 mAb ligation, Gα16/PLCβ siRNA, K⁺ efflux measurement, NLRP3 activation assays in THP-1 and primary monocytes","pmids":["33488598"],"confidence":"High","gaps":["Whether EMR2 is required for NLRP3 activation in vivo not tested","Relative contribution vs. other pattern-recognition receptors unknown"]},{"year":2024,"claim":"In AML, ADGRE2 was shown to sustain leukemic stem cell proteostasis through a PLCβ/PKC/MEK/ERK/AP1 axis that transcriptionally upregulates DUSP1, which in turn dephosphorylates DNAJB1 to enable HSP70 co-chaperone function, revealing a non-immune pro-survival role.","evidence":"ADGRE2 silencing in AML lines and patient-derived cells, xenograft models, ChIP-seq/RNA-seq, DUSP1 phosphorylation and co-IP of DNAJB1–HSP70","pmids":["39082681"],"confidence":"High","gaps":["Whether ADGRE2 ligand in bone marrow niche is identified","Relevance to non-AML malignancies not explored","Structural basis for selective AP1 target gene activation unknown"]},{"year":2024,"claim":"Identification of GNA15 (Gα15) as a direct physical interactor at the ADGRE2 intracellular segment that promotes leukemia cell proliferation via ERK/JNK/p38 provided additional evidence for G protein coupling in a disease context.","evidence":"Co-immunoprecipitation, BrdU proliferation assay, GNA15 siRNA knockdown, phospho-Western blotting","pmids":["39656442"],"confidence":"Medium","gaps":["Reciprocal IP not reported","Whether Gα15 and Gα16 are redundant or additive in leukemia signaling unclear"]},{"year":null,"claim":"The endogenous ligand hierarchy in vivo, the structural basis of force-induced NTF–CTF dissociation, and whether ADGRE2 represents a therapeutic target in AML remain unresolved.","evidence":"","pmids":[],"confidence":"Low","gaps":["No cryo-EM or crystal structure of full-length receptor or GAIN domain","In vivo genetic loss-of-function studies in conditional knockout mice not reported","Therapeutic targeting in AML not validated in clinical studies"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0060089","term_label":"molecular transducer activity","supporting_discovery_ids":[0,8,10,11,14,15]},{"term_id":"GO:0098772","term_label":"molecular function regulator activity","supporting_discovery_ids":[9,11,15,16]}],"localization":[{"term_id":"GO:0005886","term_label":"plasma membrane","supporting_discovery_ids":[0,1,8,9]},{"term_id":"GO:0005783","term_label":"endoplasmic reticulum","supporting_discovery_ids":[4]},{"term_id":"GO:0005576","term_label":"extracellular region","supporting_discovery_ids":[2,3,9]}],"pathway":[{"term_id":"R-HSA-162582","term_label":"Signal Transduction","supporting_discovery_ids":[11,13,14,15,16,17]},{"term_id":"R-HSA-168256","term_label":"Immune System","supporting_discovery_ids":[8,11,15]},{"term_id":"R-HSA-1643685","term_label":"Disease","supporting_discovery_ids":[10,16,17]}],"complexes":[],"partners":["GNA15","PLCB1","DUSP1","DNAJB1"],"other_free_text":[]},"mechanistic_narrative":"ADGRE2 (EMR2) is a myeloid-restricted adhesion G protein-coupled receptor that transduces mechanical and ligand-dependent signals to drive innate immune cell activation, mast cell degranulation, and leukemic stem cell maintenance. The receptor undergoes autocatalytic cis-proteolysis at the GPS/GAIN domain in the ER, generating noncovalently associated extracellular (NTF) and seven-transmembrane (CTF) subunits whose ligation-induced redistribution into lipid rafts initiates Gα16/Gαz-coupled signaling through PLC-β, Akt, MAPK, and NF-κB, promoting neutrophil activation, macrophage cytokine production, and NLRP3 inflammasome priming [PMID:22310662, PMID:28421075, PMID:33488598, PMID:31969668]. The NTF binds chondroitin sulfate and dermatan sulfate glycosaminoglycans via its fourth EGF-like domain in a Ca²⁺- and sulfation-dependent manner, mediating cell–cell and cell–matrix adhesion [PMID:12829604, PMID:15693006]. The p.C492Y missense variant destabilizes subunit interaction and causes familial vibratory urticaria by sensitizing mast cells to vibration-induced degranulation [PMID:26841242]. In acute myeloid leukemia, ADGRE2 activates a PLCβ/PKC/MEK/ERK/AP1 axis that upregulates DUSP1, maintaining proteostasis in leukemic stem cells through DNAJB1–HSP70 co-chaperone regulation [PMID:39082681]."},"prefetch_data":{"uniprot":{"accession":"Q9UHX3","full_name":"Adhesion G protein-coupled receptor E2","aliases":["EGF-like module receptor 2","EGF-like module-containing mucin-like hormone receptor-like 2"],"length_aa":823,"mass_kda":90.5,"function":"Cell surface receptor that binds to the chondroitin sulfate moiety of glycosaminoglycan chains and promotes cell attachment. Promotes granulocyte chemotaxis, degranulation and adhesion. In macrophages, promotes the release of inflammatory cytokines, including IL8 and TNF. Signals probably through G-proteins. Is a regulator of mast cell degranulation (PubMed:26841242)","subcellular_location":"Cell membrane; Cell projection, ruffle membrane","url":"https://www.uniprot.org/uniprotkb/Q9UHX3/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/ADGRE2","classification":"Not Classified","n_dependent_lines":27,"n_total_lines":1208,"dependency_fraction":0.022350993377483443},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/ADGRE2","total_profiled":1310},"omim":[{"mim_id":"606100","title":"ADHESION G PROTEIN-COUPLED RECEPTOR E2; ADGRE2","url":"https://www.omim.org/entry/606100"},{"mim_id":"125630","title":"VIBRATORY URTICARIA; VBU","url":"https://www.omim.org/entry/125630"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Uncertain","locations":[{"location":"Vesicles","reliability":"Uncertain"},{"location":"Cytosol","reliability":"Additional"}],"tissue_specificity":"Tissue enhanced","tissue_distribution":"Detected in many","driving_tissues":[{"tissue":"lymphoid tissue","ntpm":18.3}],"url":"https://www.proteinatlas.org/search/ADGRE2"},"hgnc":{"alias_symbol":["CD312"],"prev_symbol":["EMR2"]},"alphafold":{"accession":"Q9UHX3","domains":[{"cath_id":"2.10.25.10","chopping":"179-213","consensus_level":"medium","plddt":80.2631,"start":179,"end":213},{"cath_id":"2.10.25.10","chopping":"228-262","consensus_level":"medium","plddt":80.9886,"start":228,"end":262},{"cath_id":"2.60.220.50","chopping":"277-526","consensus_level":"medium","plddt":82.8828,"start":277,"end":526},{"cath_id":"1.20.1070.10","chopping":"545-728","consensus_level":"high","plddt":81.5346,"start":545,"end":728}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q9UHX3","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q9UHX3-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q9UHX3-F1-predicted_aligned_error_v6.png","plddt_mean":79.31},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=ADGRE2","jax_strain_url":"https://www.jax.org/strain/search?query=ADGRE2"},"sequence":{"accession":"Q9UHX3","fasta_url":"https://rest.uniprot.org/uniprotkb/Q9UHX3.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q9UHX3/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q9UHX3"}},"corpus_meta":[{"pmid":"12829604","id":"PMC_12829604","title":"The epidermal growth factor-like domains of the human EMR2 receptor mediate cell attachment through chondroitin sulfate glycosaminoglycans.","date":"2003","source":"Blood","url":"https://pubmed.ncbi.nlm.nih.gov/12829604","citation_count":172,"is_preprint":false},{"pmid":"15150276","id":"PMC_15150276","title":"Autocatalytic cleavage of the EMR2 receptor occurs at a conserved G protein-coupled receptor proteolytic site motif.","date":"2004","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/15150276","citation_count":170,"is_preprint":false},{"pmid":"26841242","id":"PMC_26841242","title":"Vibratory Urticaria Associated with a Missense Variant in ADGRE2.","date":"2016","source":"The New England journal of medicine","url":"https://pubmed.ncbi.nlm.nih.gov/26841242","citation_count":150,"is_preprint":false},{"pmid":"10903844","id":"PMC_10903844","title":"Human EMR2, a novel EGF-TM7 molecule on chromosome 19p13.1, is closely related to CD97.","date":"2000","source":"Genomics","url":"https://pubmed.ncbi.nlm.nih.gov/10903844","citation_count":85,"is_preprint":false},{"pmid":"29072692","id":"PMC_29072692","title":"miR-99a reveals two novel oncogenic proteins E2F2 and EMR2 and represses stemness in lung cancer.","date":"2017","source":"Cell death & disease","url":"https://pubmed.ncbi.nlm.nih.gov/29072692","citation_count":83,"is_preprint":false},{"pmid":"17928360","id":"PMC_17928360","title":"Ligation of the adhesion-GPCR EMR2 regulates human neutrophil function.","date":"2007","source":"FASEB journal : official publication of the Federation of American Societies for Experimental Biology","url":"https://pubmed.ncbi.nlm.nih.gov/17928360","citation_count":82,"is_preprint":false},{"pmid":"15498814","id":"PMC_15498814","title":"Expression of the largest CD97 and EMR2 isoforms on leukocytes facilitates a specific interaction with chondroitin sulfate on B cells.","date":"2004","source":"Journal of leukocyte biology","url":"https://pubmed.ncbi.nlm.nih.gov/15498814","citation_count":73,"is_preprint":false},{"pmid":"12428789","id":"PMC_12428789","title":"CD97, but not its closely related EGF-TM7 family member EMR2, is expressed on gastric, pancreatic, and esophageal carcinomas.","date":"2002","source":"American journal of clinical pathology","url":"https://pubmed.ncbi.nlm.nih.gov/12428789","citation_count":73,"is_preprint":false},{"pmid":"11994511","id":"PMC_11994511","title":"The human EGF-TM7 family member EMR2 is a heterodimeric receptor expressed on myeloid cells.","date":"2002","source":"Journal of leukocyte biology","url":"https://pubmed.ncbi.nlm.nih.gov/11994511","citation_count":57,"is_preprint":false},{"pmid":"12860403","id":"PMC_12860403","title":"Proteolytic cleavage of the EMR2 receptor requires both the extracellular stalk and the GPS motif.","date":"2003","source":"FEBS letters","url":"https://pubmed.ncbi.nlm.nih.gov/12860403","citation_count":54,"is_preprint":false},{"pmid":"22310662","id":"PMC_22310662","title":"Activation of myeloid cell-specific adhesion class G protein-coupled receptor EMR2 via ligation-induced translocation and interaction of receptor subunits in lipid raft microdomains.","date":"2012","source":"Molecular and cellular biology","url":"https://pubmed.ncbi.nlm.nih.gov/22310662","citation_count":50,"is_preprint":false},{"pmid":"26153037","id":"PMC_26153037","title":"Expression of CD11c and EMR2 on neutrophils: potential diagnostic biomarkers for sepsis and systemic inflammation.","date":"2015","source":"Clinical and experimental immunology","url":"https://pubmed.ncbi.nlm.nih.gov/26153037","citation_count":47,"is_preprint":false},{"pmid":"15693006","id":"PMC_15693006","title":"Identification of the epidermal growth factor-TM7 receptor EMR2 and its ligand dermatan sulfate in rheumatoid synovial 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pathology","url":"https://pubmed.ncbi.nlm.nih.gov/12761622","citation_count":17,"is_preprint":false},{"pmid":"20167235","id":"PMC_20167235","title":"Differential expression of the EGF-TM7 family members CD97 and EMR2 in lipid-laden macrophages in atherosclerosis, multiple sclerosis and Gaucher disease.","date":"2010","source":"Immunology letters","url":"https://pubmed.ncbi.nlm.nih.gov/20167235","citation_count":17,"is_preprint":false},{"pmid":"33488598","id":"PMC_33488598","title":"Stimulation of Vibratory Urticaria-Associated Adhesion-GPCR, EMR2/ADGRE2, Triggers the NLRP3 Inflammasome Activation Signal in Human Monocytes.","date":"2021","source":"Frontiers in immunology","url":"https://pubmed.ncbi.nlm.nih.gov/33488598","citation_count":16,"is_preprint":false},{"pmid":"31594642","id":"PMC_31594642","title":"The role of the RGD motif in CD97/ADGRE5-and EMR2/ADGRE2-modulated tumor angiogenesis.","date":"2019","source":"Biochemical and biophysical research 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Section D, Biological crystallography","url":"https://pubmed.ncbi.nlm.nih.gov/15103144","citation_count":10,"is_preprint":false},{"pmid":"23554678","id":"PMC_23554678","title":"Comparative domain modeling of human EGF-like module EMR2 and study of interaction of the fourth domain of EGF with chondroitin 4-sulphate.","date":"2011","source":"Journal of biomedical research","url":"https://pubmed.ncbi.nlm.nih.gov/23554678","citation_count":5,"is_preprint":false},{"pmid":"40144939","id":"PMC_40144939","title":"Research Progress of EMR2 Receptor Function in Glioma and its Potential Application as Therapeutic Target.","date":"2024","source":"Current health sciences journal","url":"https://pubmed.ncbi.nlm.nih.gov/40144939","citation_count":3,"is_preprint":false},{"pmid":"28437084","id":"PMC_28437084","title":"Affinity Binding of EMR2 Expressing Cells by Surface-Grafted Chondroitin Sulfate B.","date":"2017","source":"Biomacromolecules","url":"https://pubmed.ncbi.nlm.nih.gov/28437084","citation_count":3,"is_preprint":false},{"pmid":"37998392","id":"PMC_37998392","title":"The Posttraumatic Increase of the Adhesion GPCR EMR2/ADGRE2 on Circulating Neutrophils Is Not Related to Injury Severity.","date":"2023","source":"Cells","url":"https://pubmed.ncbi.nlm.nih.gov/37998392","citation_count":2,"is_preprint":false},{"pmid":"39656442","id":"PMC_39656442","title":"CD312 Promotes Paediatric Acute Lymphoblastic Leukaemia Through GNA15-Mediated Non-Classical GPCR Signalling Pathway.","date":"2024","source":"Journal of cellular and molecular medicine","url":"https://pubmed.ncbi.nlm.nih.gov/39656442","citation_count":2,"is_preprint":false},{"pmid":"40529451","id":"PMC_40529451","title":"Long-lasting changes in circulating dendritic cell and monocyte subsets, and altered expression of EMR2, CD97 and EMR3 on these cells in the posttraumatic course.","date":"2025","source":"Clinical & translational immunology","url":"https://pubmed.ncbi.nlm.nih.gov/40529451","citation_count":2,"is_preprint":false},{"pmid":"39501172","id":"PMC_39501172","title":"Investigating the role of non-synonymous variant D67N of ADGRE2 in chronic myeloid leukemia.","date":"2024","source":"BMC cancer","url":"https://pubmed.ncbi.nlm.nih.gov/39501172","citation_count":1,"is_preprint":false},{"pmid":"32184438","id":"PMC_32184438","title":"Author Correction: G Protein-Coupling of Adhesion GPCRs ADGRE2/EMR2 and ADGRE5/CD97, and Activation of G Protein Signalling by an Anti-EMR2 Antibody.","date":"2020","source":"Scientific reports","url":"https://pubmed.ncbi.nlm.nih.gov/32184438","citation_count":1,"is_preprint":false},{"pmid":"41544890","id":"PMC_41544890","title":"Myeloid-driven inflammation highlights ADGRE2 as a biomarker in prurigo nodularis: Integrated multiomics analysis.","date":"2026","source":"The Journal of investigative dermatology","url":"https://pubmed.ncbi.nlm.nih.gov/41544890","citation_count":0,"is_preprint":false},{"pmid":null,"id":"bio_10.1101_2025.08.21.671614","title":"Integrating Human Genetics and Protective Genome Editing to Enable ADGRE2-Directed AML Therapy","date":"2025-08-22","source":"bioRxiv","url":"https://doi.org/10.1101/2025.08.21.671614","citation_count":0,"is_preprint":true},{"pmid":null,"id":"bio_10.1101_2025.08.24.671942","title":"Engineering Antibody-Drug Conjugates targeting an Adhesion GPCR, CD97","date":"2025-08-28","source":"bioRxiv","url":"https://doi.org/10.1101/2025.08.24.671942","citation_count":0,"is_preprint":true}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":19559,"output_tokens":4779,"usd":0.065181},"stage2":{"model":"claude-opus-4-6","input_tokens":8353,"output_tokens":3366,"usd":0.188872},"total_usd":0.254053,"stage1_batch_id":"msgbatch_01TqNM6p6FsoMBT2jzQTwKBr","stage2_batch_id":"msgbatch_01Ya473eco8sTHbvRymQaU8o","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2000,\n      \"finding\": \"EMR2 (ADGRE2) is a member of the EGF-TM7 family of class B GPCRs, containing N-terminal EGF-like domains coupled to a seven-span transmembrane domain via a mucin-like spacer. Expression is restricted to monocytes/macrophages and granulocytes, and unlike CD97 it does not interact with CD55, indicating distinct ligand specificity.\",\n      \"method\": \"Genomic mapping, alternative splicing analysis, monoclonal antibody binding assays, flow cytometry on primary leukocytes\",\n      \"journal\": \"Genomics\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — foundational characterization with multiple orthogonal methods, highly cited\",\n      \"pmids\": [\"10903844\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2002,\n      \"finding\": \"EMR2 is expressed as a heterodimeric receptor consisting of an extracellular alpha subunit and a seven-transmembrane/cytoplasmic beta subunit, with myeloid-restricted expression (highest on CD16+ monocytes, macrophages, and BDCA-3+ myeloid DCs).\",\n      \"method\": \"Monoclonal antibody generation (2A1), immunoprecipitation, flow cytometry on primary blood leukocytes and hematopoietic cell lines, in situ analysis\",\n      \"journal\": \"Journal of leukocyte biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — reciprocal antibody-based detection and fractionation with multiple cell types, replicated across labs\",\n      \"pmids\": [\"11994511\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2003,\n      \"finding\": \"The EGF-like domains of EMR2 mediate cell attachment through chondroitin sulfate (CS) glycosaminoglycans; the fourth EGF-like module constitutes the major ligand-binding site, and the interaction is Ca2+- and sulphation-dependent.\",\n      \"method\": \"Multivalent protein probes, antibody-blocking studies, mutant CHO cell lines defective in GAG biosynthesis, enzymatic removal of cell surface GAGs, dose-dependent competition with exogenous CS\",\n      \"journal\": \"Blood\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 — reconstituted ligand interaction with genetic (mutant CHO) and enzymatic validation, highly cited\",\n      \"pmids\": [\"12829604\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2003,\n      \"finding\": \"Proteolytic cleavage of EMR2 occurs at Leu517-Ser518 within the GPS motif, is independent of transmembrane domains, requires the entire extracellular stalk (not GPS alone), and the non-covalent alpha-beta subunit association requires a minimum of eight amino acids in the beta-subunit. An alternatively spliced isoform with truncated stalk fails to undergo cleavage.\",\n      \"method\": \"Site-directed mutagenesis, cell-free cleavage assays, analysis of alternatively spliced isoforms, biochemical fractionation\",\n      \"journal\": \"FEBS letters\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 — in vitro mutagenesis and cell-free reconstitution defining exact cleavage site and requirements\",\n      \"pmids\": [\"12860403\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2004,\n      \"finding\": \"GPS autoproteolysis of EMR2 is an autocatalytic intramolecular reaction at His-Leu↓Ser518; requires Ser, Thr, or Cys at P(+1) and His at P(-2) for efficient cleavage; occurs in the ER; produces two subunits that associate noncovalently. The mechanism resembles N-terminal nucleophile hydrolases performing cis-proteolysis.\",\n      \"method\": \"Site-directed mutagenesis of GPS residues, cell-free system spontaneous hydrolysis assay, biochemical characterization of ER localization of cleavage\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 — in vitro reconstitution with mutagenesis defining catalytic mechanism, highly cited\",\n      \"pmids\": [\"15150276\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2004,\n      \"finding\": \"The fourth EGF domain of EMR2 (present on activated lymphocytes and myeloid cells) binds chondroitin sulfate specifically on B cells within peripheral blood, suggesting a role in T cell/DC/macrophage interactions with B cells.\",\n      \"method\": \"Fluorescent beads coated with recombinant CD97 and EMR2, isoform-specific monoclonal antibodies, flow cytometry on peripheral blood leukocytes\",\n      \"journal\": \"Journal of leukocyte biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — direct binding assay with isoform-specific antibodies, single lab\",\n      \"pmids\": [\"15498814\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2005,\n      \"finding\": \"In rheumatoid synovial tissue, dermatan sulfate is the endogenous ligand for the largest isoforms of EMR2 and CD97. EMR2 is expressed on macrophages and dendritic cells expressing costimulatory molecules and TNFα in synovium.\",\n      \"method\": \"Immunohistochemistry, double immunofluorescence, EMR2/CD97-specific multivalent fluorescent probe binding assays on synovial tissue sections\",\n      \"journal\": \"Arthritis and rheumatism\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — direct tissue binding assay with specific probes identifying endogenous ligand in vivo\",\n      \"pmids\": [\"15693006\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2006,\n      \"finding\": \"EMR2 expression is up-regulated during macrophage differentiation/maturation and down-regulated during dendritic cell maturation; LPS and IL-10 (via an IL-10-mediated pathway) specifically up-regulate EMR2 in monocytes and macrophages. Alternative splicing and glycosylation of EMR2 are regulated during myeloid differentiation.\",\n      \"method\": \"Flow cytometry, ELISA, immunohistochemistry, specific mAb-based detection of isoforms, siRNA/inhibitor dissection of LPS/IL-10 pathways\",\n      \"journal\": \"Biochemical and biophysical research communications\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — multiple methods in single lab defining regulatory pathway\",\n      \"pmids\": [\"17174274\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2007,\n      \"finding\": \"Ligation of EMR2 on neutrophils increases adhesion, migration, superoxide production, and proteolytic enzyme degranulation by potentiating proinflammatory mediator effects; upon activation EMR2 translocates to membrane ruffles and the leading edge; the transmembrane region is critical for these signaling functions.\",\n      \"method\": \"Anti-EMR2 antibody ligation, superoxide assay, degranulation assay, live-cell imaging showing translocation to membrane ruffles, dominant-negative transmembrane domain constructs\",\n      \"journal\": \"FASEB journal\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — multiple functional readouts with mechanistic dissection of transmembrane domain requirement, replicated across multiple proinflammatory stimuli\",\n      \"pmids\": [\"17928360\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"GPS autoproteolysis produces two distinct EMR2 receptor complexes: a noncovalent alpha-beta heterodimer and two completely independent subunits that distribute differentially in lipid raft microdomains. Receptor ligation induces subunit translocation and colocalization within lipid rafts, leading to signaling and inflammatory cytokine production by macrophages.\",\n      \"method\": \"Biochemical fractionation of lipid rafts, co-immunoprecipitation, antibody-mediated ligation, cytokine ELISA, GPS mutant constructs\",\n      \"journal\": \"Molecular and cellular biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1–2 — GPS mutagenesis combined with lipid raft fractionation and functional cytokine readout, mechanistically resolves subunit distribution\",\n      \"pmids\": [\"22310662\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"A missense variant p.C492Y in ADGRE2 causes familial vibratory urticaria by destabilizing the autoinhibitory noncovalent subunit interaction between the extracellular and transmembrane subunits, sensitizing mast cells to IgE-independent vibration-induced degranulation.\",\n      \"method\": \"Human genetics (variant co-segregation in two kindreds), biochemical subunit interaction assays, mast cell degranulation assays with vibration stimulation\",\n      \"journal\": \"The New England journal of medicine\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — co-segregation genetics plus biochemical subunit destabilization assay and functional mast cell degranulation, highly cited\",\n      \"pmids\": [\"26841242\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"Activation of EMR2 via agonistic antibody promotes THP-1 monocyte differentiation and induces IL-8, TNF-α, and MMP-9 expression through a Gα16-initiated signaling cascade activating Akt, ERK, JNK, and NF-κB.\",\n      \"method\": \"Anti-EMR2 antibody ligation, specific signaling inhibitors, siRNA knockdowns of pathway components, ELISA for cytokines, flow cytometry for differentiation markers\",\n      \"journal\": \"Frontiers in immunology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — siRNA knockdown of specific G protein combined with inhibitor dissection and multiple functional readouts\",\n      \"pmids\": [\"28421075\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"The membrane-associated NTF (N-terminal fragment) of EMR2 is regulated by site-specific N-glycosylation in the GAIN domain occurring in post-ER compartments; a unique amphipathic alpha-helix in the GAIN domain serves as a putative membrane anchor of the NTF, independent of the CTF.\",\n      \"method\": \"Glycosylation site mutagenesis, subcellular fractionation, glycosidase treatment, confocal imaging of compartment-specific localization\",\n      \"journal\": \"Scientific reports\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 1–2 — mutagenesis of glycosylation sites combined with fractionation, single lab\",\n      \"pmids\": [\"29540735\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"ADGRE2/EMR2 couples broadly to G proteins (Gα16, Gα12, Gα13, Gα14, Gαz, Gα16/Gαz chimera) as shown by activated truncated receptor forms; EMR2 signals via Gα16 to stimulate IP1 accumulation and induces pertussis-toxin-insensitive inhibition of cAMP, suggesting Gαz coupling. An anti-EMR2 polyclonal antibody activates G protein signaling in vitro.\",\n      \"method\": \"Yeast-based G protein coupling assay with chimeric G proteins, mammalian cAMP assay with pertussis toxin, IP1 accumulation assay, NFAT reporter assay\",\n      \"journal\": \"Scientific reports\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1–2 — multiple recombinant systems and pharmacological dissection across multiple G protein subtypes\",\n      \"pmids\": [\"31969668\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"Mechanical activation (vibration) of mast cells expressing p.C492Y-ADGRE2 attached to dermatan sulfate activates phospholipase C, causing transient cytosolic Ca2+ increase and downstream activation of PI3K and ERK1/2 via Gβγ, Gαq/11, and Gαi/o-independent mechanisms; degranulation requires PLC/Ca2+/PKC/PI3K pathways plus pertussis toxin-sensitive signals; prostaglandin D2 synthesis requires ERK1/2, Ca2+, PKC, and PI3K.\",\n      \"method\": \"Vibration stimulation of primary human mast cells, Ca2+ imaging, pharmacological inhibitors of PLC/PI3K/PKC/ERK, pertussis toxin treatment, degranulation assay, prostaglandin D2 ELISA\",\n      \"journal\": \"The Journal of investigative dermatology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — pharmacological dissection with multiple inhibitors in primary human mast cells with multiple functional readouts\",\n      \"pmids\": [\"32222457\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"EMR2 activation by agonistic antibody triggers the NLRP3 inflammasome activation (2nd) signal in THP-1 monocytes and primary monocytes via Gα16-dependent PLC-β activation, leading to Akt, MAPK, NF-κB activity, Ca2+ mobilization, and K+ efflux.\",\n      \"method\": \"Anti-EMR2 mAb ligation, siRNA knockdown of Gα16 and PLC-β, K+ efflux measurement, NLRP3 inflammasome activation assays, pharmacological inhibitors\",\n      \"journal\": \"Frontiers in immunology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — siRNA knockdown of specific G protein subunit combined with multiple downstream pathway readouts\",\n      \"pmids\": [\"33488598\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"ADGRE2 activates a PLCβ/PKC/MEK/ERK signaling cascade that drives AP1 transcriptional activity, which in turn transcriptionally upregulates DUSP1; DUSP1 dephosphorylates Ser16 of the co-chaperone DNAJB1 to facilitate DNAJB1-HSP70 interaction and maintain proteostasis in AML leukemic stem cells.\",\n      \"method\": \"ADGRE2 silencing in AML cell lines and patient-derived cells, xenograft mouse models, ChIP-seq/RNA-seq for AP1 targets, DUSP1 phosphorylation assays, co-immunoprecipitation of DNAJB1-HSP70, combined MEK/AP1/DUSP1 inhibitor treatment\",\n      \"journal\": \"Cancer research\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — multiple orthogonal methods including KO, in vivo xenograft, co-IP, and phosphorylation assays in a single study\",\n      \"pmids\": [\"39082681\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"CD312/ADGRE2 interacts with GNA15 (Gα15) at the transmembrane intracellular segment, and this interaction promotes leukaemia cell proliferation via phosphorylation of ERK, JNK, and p38 in a co-culture system; GNA15 knockdown abrogates this proliferative effect.\",\n      \"method\": \"Co-immunoprecipitation (GNA15-CD312 interaction), BrdU proliferation assay, GNA15 siRNA knockdown, phospho-Western blotting for ERK/JNK/p38\",\n      \"journal\": \"Journal of cellular and molecular medicine\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2–3 — Co-IP plus functional siRNA knockdown, single lab\",\n      \"pmids\": [\"39656442\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"EMR2 contains an SGD sequence (corresponding to RGD in CD97) that prevents integrin α5β1 binding and angiogenesis induction; substituting SGD→RGD in EMR2 enables it to upregulate MMP-9 and induce angiogenesis via N-cadherin-regulated MMP-9 expression, similar to CD97.\",\n      \"method\": \"Site-directed mutagenesis of RGD/SGD motif, in vitro endothelial tube formation assay, in ovo chick CAM assay, MMP-9 expression analysis, N-cadherin modulation experiments\",\n      \"journal\": \"Biochemical and biophysical research communications\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 1–2 — mutagenesis with in vitro and in vivo angiogenesis functional readouts, single lab\",\n      \"pmids\": [\"31594642\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"ADGRE2/EMR2 is a myeloid-restricted adhesion GPCR that undergoes autocatalytic GPS/GAIN-domain cis-proteolysis in the ER to generate noncovalently associated extracellular (NTF) and seven-transmembrane (CTF) subunits; the NTF binds chondroitin/dermatan sulfate glycosaminoglycans via its fourth EGF-like domain, and mechanical or antibody-mediated receptor ligation induces lipid-raft translocation and Gα16/Gαz-coupled signaling through PLC-β, Akt, MAPK, and NF-κB to drive neutrophil and macrophage activation, mast cell degranulation (sensitized by the disease-causing p.C492Y variant that destabilizes subunit interaction), NLRP3 inflammasome priming, and in AML a PLCβ/PKC/MEK/ERK/AP1/DUSP1 axis that sustains proteostasis in leukemic stem cells.\"\n}\n```","stage2_raw":"```json\n{\n  \"mechanistic_narrative\": \"ADGRE2 (EMR2) is a myeloid-restricted adhesion G protein-coupled receptor that transduces mechanical and ligand-dependent signals to drive innate immune cell activation, mast cell degranulation, and leukemic stem cell maintenance. The receptor undergoes autocatalytic cis-proteolysis at the GPS/GAIN domain in the ER, generating noncovalently associated extracellular (NTF) and seven-transmembrane (CTF) subunits whose ligation-induced redistribution into lipid rafts initiates Gα16/Gαz-coupled signaling through PLC-β, Akt, MAPK, and NF-κB, promoting neutrophil activation, macrophage cytokine production, and NLRP3 inflammasome priming [PMID:22310662, PMID:28421075, PMID:33488598, PMID:31969668]. The NTF binds chondroitin sulfate and dermatan sulfate glycosaminoglycans via its fourth EGF-like domain in a Ca²⁺- and sulfation-dependent manner, mediating cell–cell and cell–matrix adhesion [PMID:12829604, PMID:15693006]. The p.C492Y missense variant destabilizes subunit interaction and causes familial vibratory urticaria by sensitizing mast cells to vibration-induced degranulation [PMID:26841242]. In acute myeloid leukemia, ADGRE2 activates a PLCβ/PKC/MEK/ERK/AP1 axis that upregulates DUSP1, maintaining proteostasis in leukemic stem cells through DNAJB1–HSP70 co-chaperone regulation [PMID:39082681].\",\n  \"teleology\": [\n    {\n      \"year\": 2000,\n      \"claim\": \"Identification of EMR2 as a novel EGF-TM7 family GPCR with myeloid-restricted expression established the receptor as distinct from the related CD97 and defined its lineage specificity.\",\n      \"evidence\": \"Genomic cloning, splice analysis, mAb binding, and flow cytometry on primary leukocytes\",\n      \"pmids\": [\"10903844\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"No ligand identified\", \"No signaling mechanism defined\", \"Functional role in myeloid cells unknown\"]\n    },\n    {\n      \"year\": 2002,\n      \"claim\": \"Demonstration that EMR2 exists as a heterodimeric receptor with an extracellular α-subunit and a TM β-subunit resolved its biochemical architecture and refined its expression to CD16+ monocytes and myeloid DCs.\",\n      \"evidence\": \"Monoclonal antibody immunoprecipitation and flow cytometry across primary blood cell populations\",\n      \"pmids\": [\"11994511\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Mechanism of heterodimer formation unknown\", \"Subunit stoichiometry not addressed\"]\n    },\n    {\n      \"year\": 2003,\n      \"claim\": \"Identification of chondroitin sulfate GAGs as the ligand for the fourth EGF-like domain and mapping of the GPS cleavage site to Leu517↓Ser518 established the receptor's extracellular recognition mechanism and its autoproteolytic processing requirements.\",\n      \"evidence\": \"Multivalent probes on mutant CHO cells defective in GAG synthesis; site-directed mutagenesis and cell-free cleavage assays\",\n      \"pmids\": [\"12829604\", \"12860403\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Whether GPS cleavage is required for signaling not tested\", \"In vivo GAG ligand identity unconfirmed\"]\n    },\n    {\n      \"year\": 2004,\n      \"claim\": \"Establishing that GPS cleavage is an autocatalytic intramolecular cis-proteolysis occurring in the ER with N-terminal nucleophile hydrolase-like chemistry defined the biogenesis mechanism of the two-subunit receptor.\",\n      \"evidence\": \"Site-directed mutagenesis of catalytic residues (His, Ser518), cell-free spontaneous hydrolysis, ER localization analysis\",\n      \"pmids\": [\"15150276\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Structural basis of autocatalysis not resolved at atomic level\", \"Whether all splice isoforms are equally processed unclear\"]\n    },\n    {\n      \"year\": 2006,\n      \"claim\": \"Showing that EMR2 expression is dynamically regulated during myeloid differentiation—up by LPS and IL-10 in macrophages, down during DC maturation—placed the receptor within innate immune activation programs.\",\n      \"evidence\": \"Flow cytometry, ELISA, mAb isoform detection, and siRNA/inhibitor dissection of LPS/IL-10 signaling in primary monocytes and macrophages\",\n      \"pmids\": [\"17174274\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Transcription factors controlling ADGRE2 expression not identified\", \"Functional consequence of isoform switching not tested\"]\n    },\n    {\n      \"year\": 2007,\n      \"claim\": \"Demonstrating that EMR2 ligation on neutrophils enhances adhesion, migration, superoxide production, and degranulation—with requirement for the transmembrane domain—established the receptor as a functional activator of innate effector responses.\",\n      \"evidence\": \"Anti-EMR2 antibody ligation with superoxide/degranulation assays, live-cell imaging of translocation to membrane ruffles, dominant-negative TM constructs\",\n      \"pmids\": [\"17928360\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Downstream G protein identity not determined\", \"Physiological ligand triggering in vivo not shown\"]\n    },\n    {\n      \"year\": 2012,\n      \"claim\": \"Resolution of two distinct post-cleavage receptor complexes—noncovalent heterodimer and independent subunits—and their differential lipid-raft distribution revealed that ligation-induced raft coalescence is the proximal signaling event driving macrophage cytokine production.\",\n      \"evidence\": \"Lipid raft fractionation, co-immunoprecipitation, GPS mutant constructs, and cytokine ELISA after antibody ligation\",\n      \"pmids\": [\"22310662\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"How raft translocation activates specific G proteins unresolved\", \"Relative contribution of heterodimer vs. independent subunits to signaling unclear\"]\n    },\n    {\n      \"year\": 2016,\n      \"claim\": \"Discovery that p.C492Y destabilizes NTF–CTF interaction and causes familial vibratory urticaria linked mechanical force sensing to subunit dissociation as the activation mechanism and established the first Mendelian disease for an adhesion GPCR.\",\n      \"evidence\": \"Co-segregation in two kindreds, biochemical subunit interaction assays, vibration-induced mast cell degranulation\",\n      \"pmids\": [\"26841242\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Structural consequence of C492Y at atomic resolution unknown\", \"Whether other destabilizing variants cause related phenotypes untested\"]\n    },\n    {\n      \"year\": 2017,\n      \"claim\": \"Identification of Gα16 as the coupling partner initiating a PLC-β/Akt/ERK/JNK/NF-κB signaling cascade upon EMR2 activation resolved the G protein identity and downstream pathway architecture in monocytes.\",\n      \"evidence\": \"siRNA knockdown of Gα16, specific inhibitors of PLC-β/Akt/ERK/JNK/NF-κB, ELISA for IL-8/TNF-α/MMP-9 in THP-1 cells\",\n      \"pmids\": [\"28421075\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Whether Gα16 is the sole coupling partner in all myeloid lineages unclear\", \"Direct Gα16–receptor interaction not shown biochemically\"]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"Comprehensive G protein coupling profiling revealed broad coupling to Gα16, Gα12/13, Gα14, and Gαz, while pharmacological dissection of vibration-stimulated mast cells mapped degranulation to PLC/Ca²⁺/PKC/PI3K plus pertussis-toxin-sensitive signals, defining the full signaling repertoire.\",\n      \"evidence\": \"Yeast chimeric G protein coupling assay, mammalian cAMP/IP1 assays, Ca²⁺ imaging and pharmacological inhibitor panel in primary mast cells\",\n      \"pmids\": [\"31969668\", \"32222457\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Gβγ subunit composition not identified\", \"Whether mechanical vs. ligand-mediated activation engages identical G protein sets untested\"]\n    },\n    {\n      \"year\": 2021,\n      \"claim\": \"Showing that EMR2 provides the second activation signal for NLRP3 inflammasome assembly via Gα16–PLCβ–dependent K⁺ efflux and Ca²⁺ mobilization extended the receptor's role to inflammasome biology.\",\n      \"evidence\": \"Anti-EMR2 mAb ligation, Gα16/PLCβ siRNA, K⁺ efflux measurement, NLRP3 activation assays in THP-1 and primary monocytes\",\n      \"pmids\": [\"33488598\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Whether EMR2 is required for NLRP3 activation in vivo not tested\", \"Relative contribution vs. other pattern-recognition receptors unknown\"]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"In AML, ADGRE2 was shown to sustain leukemic stem cell proteostasis through a PLCβ/PKC/MEK/ERK/AP1 axis that transcriptionally upregulates DUSP1, which in turn dephosphorylates DNAJB1 to enable HSP70 co-chaperone function, revealing a non-immune pro-survival role.\",\n      \"evidence\": \"ADGRE2 silencing in AML lines and patient-derived cells, xenograft models, ChIP-seq/RNA-seq, DUSP1 phosphorylation and co-IP of DNAJB1–HSP70\",\n      \"pmids\": [\"39082681\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Whether ADGRE2 ligand in bone marrow niche is identified\", \"Relevance to non-AML malignancies not explored\", \"Structural basis for selective AP1 target gene activation unknown\"]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Identification of GNA15 (Gα15) as a direct physical interactor at the ADGRE2 intracellular segment that promotes leukemia cell proliferation via ERK/JNK/p38 provided additional evidence for G protein coupling in a disease context.\",\n      \"evidence\": \"Co-immunoprecipitation, BrdU proliferation assay, GNA15 siRNA knockdown, phospho-Western blotting\",\n      \"pmids\": [\"39656442\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Reciprocal IP not reported\", \"Whether Gα15 and Gα16 are redundant or additive in leukemia signaling unclear\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"The endogenous ligand hierarchy in vivo, the structural basis of force-induced NTF–CTF dissociation, and whether ADGRE2 represents a therapeutic target in AML remain unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"No cryo-EM or crystal structure of full-length receptor or GAIN domain\", \"In vivo genetic loss-of-function studies in conditional knockout mice not reported\", \"Therapeutic targeting in AML not validated in clinical studies\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0060089\", \"supporting_discovery_ids\": [0, 8, 10, 11, 14, 15]},\n      {\"term_id\": \"GO:0098772\", \"supporting_discovery_ids\": [9, 11, 15, 16]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005886\", \"supporting_discovery_ids\": [0, 1, 8, 9]},\n      {\"term_id\": \"GO:0005783\", \"supporting_discovery_ids\": [4]},\n      {\"term_id\": \"GO:0005576\", \"supporting_discovery_ids\": [2, 3, 9]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-162582\", \"supporting_discovery_ids\": [11, 13, 14, 15, 16, 17]},\n      {\"term_id\": \"R-HSA-168256\", \"supporting_discovery_ids\": [8, 11, 15]},\n      {\"term_id\": \"R-HSA-1643685\", \"supporting_discovery_ids\": [10, 16, 17]}\n    ],\n    \"complexes\": [],\n    \"partners\": [\n      \"GNA15\",\n      \"PLCB1\",\n      \"DUSP1\",\n      \"DNAJB1\"\n    ],\n    \"other_free_text\": []\n  }\n}\n```"}