| 2000 |
EMR2 (ADGRE2) is a member of the EGF-TM7 family of class B GPCRs, contains five tandem EGF-like domains coupled to a seven-span transmembrane domain via a mucin-like spacer, and expresses multiple protein isoforms via alternative RNA splicing. Expression is restricted to monocytes/macrophages and granulocytes, unlike the ubiquitously expressed paralog CD97. EMR2 fails to interact with CD55, the cellular ligand for CD97, indicating distinct ligand specificity. |
Genomic mapping, molecular cloning, monoclonal antibody generation, flow cytometry, ligand-binding assays |
Genomics |
Medium |
10903844
|
| 2002 |
EMR2 is expressed as a heterodimeric receptor on the cell surface, consisting of an extracellular alpha subunit and a seven-pass transmembrane/cytoplasmic beta subunit. Expression is restricted to myeloid cells (highest on CD16+ monocytes, macrophages, and BDCA-3+ myeloid DC), and EMR2 does not interact with CD55 (the CD97 ligand), confirming non-redundant functions for the two molecular twins. |
Monoclonal antibody generation (2A1), immunoprecipitation, flow cytometry on primary blood leukocytes, hematopoietic cell lines, and in situ tissue analysis |
Journal of leukocyte biology |
Medium |
11994511
|
| 2003 |
The largest EMR2 isoform (containing 5 EGF-like modules) mediates cell attachment through binding to chondroitin sulfate (CS) glycosaminoglycans. The fourth EGF-like module is the major ligand-binding site. The interaction is Ca2+- and sulphation-dependent. Mutant CHO cell lines defective in GAG biosynthesis and enzymatic removal of cell-surface GAGs demonstrated that CS is the molecular identity of the EMR2 ligand. Exogenous CS GAGs blocked the interaction in a dose-dependent manner. |
Multivalent protein probes, antibody-blocking studies, mutant CHO cell lines (GAG biosynthesis-deficient), enzymatic GAG removal, dose-dependent inhibition assays |
Blood |
High |
12829604
|
| 2003 |
Proteolytic cleavage of EMR2 occurs at Leu517-Ser518 within the GPS motif and is independent of the transmembrane domains. The non-covalent association of the resulting extracellular alpha-subunit and transmembrane beta-subunit requires a minimum of eight amino acids in the beta-subunit. The GPS motif is necessary but not sufficient for cleavage; the entire extracellular stalk is required. An alternatively spliced EMR2 isoform with a truncated stalk fails to undergo proteolytic cleavage, demonstrating that alternative splicing regulates GPS cleavage. |
Site-directed mutagenesis, biochemical cleavage assays, analysis of alternatively spliced isoforms, cell-free system |
FEBS letters |
High |
12860403
|
| 2004 |
GPS proteolysis of EMR2 is an autocatalytic intramolecular reaction. Cleavage occurs at the conserved His-Leu↓Ser518 site inside the endoplasmic reticulum, producing two protein subunits that associate non-covalently as a heterodimer. The P(+1) Ser518 residue (Ser, Thr, or Cys) is absolutely required for efficient proteolysis. Substitution of the P(-2) His residue produces slow-processing precursor proteins that spontaneously hydrolyze in a cell-free system, indicating the mechanism is similar to N-terminal nucleophile hydrolases performing cis-proteolysis. |
Site-directed mutagenesis of cleavage site residues, cell-free proteolysis assay, biochemical characterization of processing intermediates |
The Journal of biological chemistry |
High |
15150276
|
| 2004 |
The fourth EGF domain of both CD97 and EMR2 is expressed on activated lymphocytes and myeloid cells and mediates binding to chondroitin sulfate specifically found on B cells within peripheral blood, suggesting a role in interaction of activated T cells, dendritic cells, and macrophages with B cells. |
Fluorescent beads coated with recombinant CD97 and EMR2 protein, isoform-specific monoclonal antibodies, flow cytometry on primary leukocytes |
Journal of leukocyte biology |
Medium |
15498814
|
| 2005 |
Dermatan sulfate (a chondroitin sulfate variant) is identified as the ligand of the largest isoforms of EMR2 and CD97 in rheumatoid synovial tissue. EMR2 is expressed on macrophages and dendritic cells expressing costimulatory molecules and TNF-α in RA synovium. EMR2 expression in the synovial sublining is significantly higher in RA patients compared with OA and ReA controls. |
Immunohistochemistry with anti-EMR2 mAb, digital image analysis, double immunofluorescence microscopy, multivalent fluorescent probe binding assays on synovial tissue sections |
Arthritis and rheumatism |
Medium |
15693006
|
| 2006 |
EMR2 receptor expression is up-regulated during differentiation and maturation of macrophages, and down-regulated during dendritic cell maturation. In monocytes and macrophages, EMR2 is specifically up-regulated by LPS and IL-10 via an IL-10-mediated pathway. Alternative splicing and glycosylation of EMR2 are regulated during myeloid differentiation. |
Flow cytometry, quantitative PCR, functional stimulation assays with LPS and cytokines, analysis of primary myeloid cells during differentiation |
Biochemical and biophysical research communications |
Medium |
17174274
|
| 2007 |
Ligation of EMR2 via a specific antibody increases neutrophil adhesion and migration, augments superoxide production and proteolytic enzyme degranulation, and potentiates the effects of proinflammatory mediators. Upon neutrophil activation, EMR2 is rapidly translocated to membrane ruffles and the leading edge of the cell. The transmembrane region is critical for adhesion-GPCR function. |
Anti-EMR2 antibody ligation, superoxide assay, degranulation assay, neutrophil adhesion and migration assays, live-cell imaging of receptor translocation |
FASEB journal |
High |
17928360
|
| 2012 |
GPS autoproteolysis of EMR2 generates two distinct receptor complexes: a noncovalent α-β heterodimer and two completely independent receptor subunits. These distribute differentially in membrane raft microdomains. Receptor ligation induces subunit translocation and colocalization within lipid rafts, leading to receptor signaling and inflammatory cytokine production by macrophages. GPS autoproteolysis is critical for mediating receptor signaling and cell activation. |
Lipid raft fractionation, co-immunoprecipitation, live-cell imaging, cytokine ELISA, GPS-mutant receptor constructs, macrophage stimulation assays |
Molecular and cellular biology |
High |
22310662
|
| 2011 |
EMR2 ligation suppresses LPS-induced neutrophil survival (pro-apoptotic effect). EMR2 ligation also changes the secretion profiles of multiple cytokines, including IL-6, IL-8, and MCP-1, in LPS-treated neutrophils. |
Anti-EMR2 mAb (2A1) ligation, flow cytometry (annexin-V/PI apoptosis), ELISA for cytokine secretion, reactive oxygen species assay |
Chang Gung medical journal |
Medium |
22035891
|
| 2016 |
A missense variant in ADGRE2 (p.C492Y) cosegregates with autosomal dominant vibratory urticaria in two large kindreds. The ADGRE2 receptor undergoes autocatalytic cleavage producing an extracellular subunit that noncovalently binds a transmembrane subunit. The p.C492Y variant destabilizes the autoinhibitory subunit interaction, sensitizing mast cells to IgE-independent vibration-induced degranulation. |
Genetic cosegregation analysis in human kindreds, functional studies of variant receptor in mast cells (degranulation assays), biochemical analysis of subunit interaction |
The New England journal of medicine |
High |
26841242
|
| 2017 |
Activation of EMR2 via a receptor-specific monoclonal antibody promotes differentiation of human THP-1 monocytic cells and induces expression of pro-inflammatory mediators (IL-8, TNF-α, MMP-9). EMR2-mediated signaling is initiated by Gα16, followed by sequential activation of Akt, ERK, JNK, and NF-κB. siRNA knockdown of specific signaling intermediates confirmed the pathway. |
Anti-EMR2 mAb stimulation, siRNA knockdown of signaling intermediates, specific signaling inhibitors, ELISA, western blotting, THP-1 differentiation assays |
Frontiers in immunology |
High |
28421075
|
| 2018 |
The membrane association of the EMR2 N-terminal fragment (NTF) after GPS autoproteolysis is regulated by site-specific N-glycosylation within the GAIN domain, occurring in post-ER compartments. A unique amphipathic α-helix in the GAIN domain serves as a putative membrane anchor for the membrane-associated NTF subtype. |
Glycosylation site mutagenesis, subcellular fractionation, biochemical characterization of NTF subtypes, domain deletion analysis |
Scientific reports |
Medium |
29540735
|
| 2020 |
ADGRE2/EMR2 and ADGRE5/CD97 are functionally G protein-coupled receptors. Using activated truncated receptor forms in a yeast-based assay with chimeric G proteins, EMR2 showed broad G protein-coupling, while CD97 coupled more specifically to Gα12, Gα13, Gα14, and Gαz chimeras. Both receptors induced pertussis-toxin insensitive inhibition of cAMP, suggesting coupling to Gαz. EMR2 signals via Gα16 and a Gα16/Gαz chimera to stimulate IP1 accumulation. A polyclonal antibody was identified that activates EMR2 G protein signaling in vitro. |
Yeast-based GPCR/chimeric G protein coupling assay, cAMP inhibition assay in mammalian cells, IP1 accumulation assay, NFAT reporter assay, pertussis toxin treatment |
Scientific reports |
Medium |
31969668
|
| 2020 |
Mechanical activation (vibration) of mast cells expressing p.C492Y-ADGRE2 attached to dermatan sulfate triggers phospholipase C activation, transient cytosolic calcium increases, and downstream activation of PI3K and ERK1/2, mediated by Gβγ, Gαq/11, and through Gαi/o-independent mechanisms. Degranulation was dependent on PLC pathways (calcium, PKC, PI3K) and pertussis toxin-sensitive signals. Mechanoactivation also stimulated prostaglandin D2 synthesis via ERK1/2, calcium, PKC, and PI3K. |
Vibration stimulation of human mast cells on dermatan sulfate substrate, calcium imaging, pharmacological inhibitors of PLC/PKC/PI3K/ERK, pertussis toxin treatment, prostaglandin D2 ELISA, degranulation assay |
The Journal of investigative dermatology |
High |
32222457
|
| 2019 |
EMR2/ADGRE2 contains an SGD sequence (corresponding to the RGD integrin-binding motif in CD97). Unlike CD97, EMR2 fails to induce angiogenesis or upregulate MMP-9. However, a single change of the SGD to RGD sequence in EMR2 allows it to up-regulate MMP-9 expression, leading to enhanced angiogenesis. MMP-9 promotes HUVEC proliferation, migration, and invasion by modulating VEGF, PIGF, and bFGF levels. MMP-9 expression is modulated by N-cadherin, which is upregulated by both CD97 and EMR2/RGD. |
Site-directed mutagenesis (SGD→RGD), in vitro endothelial tube formation assay, in ovo chick chorioallantoic membrane assay, MMP-9 expression analysis, VEGF/PIGF/bFGF measurement |
Biochemical and biophysical research communications |
Medium |
31594642
|
| 2021 |
EMR2 stimulation by its agonistic 2A1 monoclonal antibody activates the NLRP3 inflammasome second signal in THP-1 monocytic cells and primary monocytes via a Gα16-dependent PLC-β activation pathway, inducing downstream Akt, MAPK, NF-κB activation and Ca2+ mobilization, ultimately leading to K+ efflux. |
Anti-EMR2 mAb (2A1) stimulation, siRNA knockdown, pharmacological inhibitors, K+ efflux measurement, Ca2+ mobilization assay, NLRP3 inflammasome activation assay in THP-1 and primary monocytes |
Frontiers in immunology |
Medium |
33488598
|
| 2024 |
ADGRE2 activates phospholipase Cβ/protein kinase C/MEK/ERK signaling to enhance expression of AP1 transcription factor, which transcriptionally drives DUSP1 (a protein phosphatase). DUSP1 dephosphorylates Ser16 in the J-domain of co-chaperone DNAJB1, facilitating the DNAJB1-HSP70 interaction and maintenance of proteostasis in AML. Silencing ADGRE2 exerts antileukemic effects in AML cell lines and patient-derived cells in vitro, and delays AML progression in xenograft models. |
siRNA/shRNA knockdown, xenograft mouse models, pharmacological inhibitors of MEK/AP1/DUSP1, phosphorylation analysis (DUSP1 Ser16), co-immunoprecipitation (DNAJB1-HSP70), transcriptional reporter assays |
Cancer research |
High |
39082681
|
| 2024 |
CD312/ADGRE2 interacts with GNA15 (Gα15) via its transmembrane intracellular segment. CD312 knockdown reduces Treg cell proportion while increasing CTL proportion in the ALL bone marrow immune microenvironment. Overexpression of CD312 in CD3+ T cells enhances leukemia cell proliferation via phosphorylation of ERK, JNK, and p38, while GNA15 knockdown decreases this proliferative effect. |
Co-immunoprecipitation/affinity assay for CD312-GNA15 interaction, CD312 knockdown and overexpression, GNA15 siRNA, BrdU proliferation assay, flow cytometry for immune subsets |
Journal of cellular and molecular medicine |
Medium |
39656442
|