| 2002 |
CD109 is a GPI-anchored glycoprotein and a novel member of the alpha2-macroglobulin/C3, C4, C5 family of thioester-containing proteins; native CD109 contains an intact thioester bond capable of covalent binding to adjacent molecules upon proteolytic activation, with complement-like reactivity (short t½, spatially restricted action). |
cDNA cloning, sequence analysis, biochemical demonstration of intact thioester in native CD109 |
Blood |
High |
11861284
|
| 2002 |
The Gov (HPA-15) platelet alloantigens are defined by a single A-to-C SNP at position 2108 of the CD109 coding region, resulting in a Tyr703Ser substitution; CHO cells transfected with the respective cDNA variants are specifically recognized by allele-specific antisera, confirming this polymorphism as the alloantigen determinant. |
RT-PCR, allele-specific PCR-SSP, PCR-RFLP, real-time PCR genotyping, CHO cell transfection with variant cDNA + serological testing |
Blood |
High |
11861285
|
| 2006 |
CD109 (identified as the 150 kDa GPI-anchored TGF-β1-binding protein r150 in keratinocytes) is a component of the TGF-β receptor system and a negative modulator of TGF-β responses; loss-of-function and gain-of-function studies show CD109 inhibits TGF-β signaling independently of ligand sequestration, likely by direct modulation of receptor activity; CD109 contains an internal thioester bond. |
Affinity purification and microsequencing of r150, biochemical thioester demonstration, siRNA knockdown (loss-of-function) and CD109 overexpression (gain-of-function) with TGF-β signaling readouts |
FASEB journal |
High |
16754747
|
| 2010 |
CD109 is processed in the Golgi by furin (furinase) from a 205 kDa precursor into 180 kDa and 25 kDa fragments; the 180 kDa form associates with GPI-anchored 25 kDa CD109 on the cell surface and is secreted. Furin cleavage (at RRRR motif, Arg1273) is required for CD109 to associate with TβRI and to inhibit TGF-β signaling; the furin-cleavage-deficient mutant (R1273S) neither impairs TGF-β signaling nor associates with TβRI. |
Western blotting of CD109 processing products, site-directed mutagenesis of furin cleavage site (R1273S), co-immunoprecipitation of CD109 with TβRI, TGF-β signaling assays |
Oncogene |
High |
20101215
|
| 2011 |
CD109 associates with caveolin-1 and promotes internalization and degradation of TGF-β receptors via the caveolae pathway; CD109 increases TGF-β binding to its receptors, enhances their internalization via caveolae, localizes TGF-β receptors to the caveolar compartment in a ligand-dependent manner, and facilitates receptor degradation, thereby inhibiting TGF-β signaling. |
Co-immunoprecipitation of CD109 with caveolin-1, immunofluorescence localization, receptor degradation assays, TGF-β binding assays, caveolae pathway inhibitors |
Biochimica et biophysica acta |
High |
21295082
|
| 2012 |
CD109 enhances SMAD7/Smurf2-mediated degradation of TGFBR1 in a ligand-dependent manner; CD109 regulates the subcellular localization and association of SMAD7/Smurf2 with TGFBR1; CD109's inhibitory effect on TGF-β signaling requires SMAD7 expression and Smurf2 ubiquitin ligase activity. |
Co-immunoprecipitation, immunofluorescence localization, SMAD7 siRNA knockdown, Smurf2 ubiquitin ligase activity assays, TGF-β receptor degradation assays |
Journal of cellular biochemistry |
High |
21898545
|
| 2011 |
CD109 released from the keratinocyte cell surface (soluble CD109) downregulates TGF-β signaling and TGF-β receptor expression, and increases STAT3 phosphorylation, total STAT3, Bcl-2 expression, and cell growth/survival; decreased CD109 protein in psoriatic epidermis (with unchanged mRNA) suggests enhanced CD109 release as a disease mechanism. |
CD109 shedding experiments, addition of recombinant CD109 protein to keratinocytes, western blotting, immunohistochemistry of psoriatic vs. normal skin |
Experimental dermatology |
Medium |
21539622
|
| 2009 |
Mesotrypsin (PRSS3) proteolytically sheds CD109 from the cell surface of breast cancer cells; CD109 is identified as the functional proteolytic target of mesotrypsin using proteomic methods; mesotrypsin knockdown attenuates and recombinant mesotrypsin enhances the malignant growth phenotype. |
Proteomic identification of CD109 as mesotrypsin substrate, PRSS3 knockdown, recombinant mesotrypsin treatment, 3D organotypic culture morphological assays |
Breast cancer research and treatment |
Medium |
20035377
|
| 2012 |
CD109-deficient mice develop epidermal hyperplasia, kinked hair shafts, ectatic hair follicles, sebum accumulation, and persistent thickening of basal/suprabasal epidermal layers; this is accompanied by elevated STAT3 phosphorylation (not elevated Smad2 phosphorylation) in the epidermis, indicating CD109 regulates keratinocyte differentiation via a STAT3-dependent pathway in vivo. |
CD109 knockout mouse generation, histological analysis, immunohistochemistry for pSmad2 and pSTAT3 |
The American journal of pathology |
High |
22846721
|
| 2013 |
Transgenic mice overexpressing CD109 in the epidermis display reduced macrophage and neutrophil recruitment, reduced granulation tissue, decreased Smad2/3 phosphorylation, decreased proinflammatory cytokines (IL-1α, MCP-1), and decreased ECM components in excisional wounds, with improved dermal collagen architecture in incisional wounds; wound closure rates are unaffected. |
CD109 transgenic mouse wound healing model, immunohistochemistry, western blotting for pSmad2/3, cytokine expression, collagen organization |
Wound repair and regeneration |
High |
23438099
|
| 2013 |
CD109 transgenic mice overexpressing CD109 in the epidermis show resistance to bleomycin-induced skin fibrosis, with significant decreases in dermal thickness, collagen crosslinking, collagen and fibronectin content, and phospho-Smad2/3 levels compared to wild-type mice. |
Bleomycin-induced scleroderma mouse model, CD109 transgenic mice, histological staining, western blotting and immunohistochemistry for pSmad2/3 |
Arthritis and rheumatism |
High |
23436317
|
| 2013 |
CD109 plays a role in osteoclastogenesis; CD109 mRNA and protein are significantly upregulated during RANKL-induced osteoclast differentiation in RAW264.7 cells, primary murine monocytes, and pre-osteoclast lines; stable CD109 knockdown reduces the formation of large multinucleated osteoclasts. |
Microarray, RT-qPCR, western blot during osteoclastogenesis, stable shRNA knockdown cell lines, osteoclast fusion assays |
PloS one |
Medium |
23593435
|
| 2015 |
Soluble CD109 (sCD109) directly binds TGF-β with high affinity (slow dissociation by surface plasmon resonance); sCD109 inhibits TGF-β binding to its receptors (radioligand competition assay), antagonizes Smad2/3 phosphorylation, and decreases TGF-β-induced transcription and cell migration. |
Surface plasmon resonance (SPR) binding kinetics, radioligand binding and affinity labelling competition assays, Smad2/3 phosphorylation assays, transcriptional reporter assays, cell migration assays |
The Biochemical journal |
High |
26621871
|
| 2015 |
Cell surface CD109 interacts with EGFR in glioblastoma SK-MG-1 cells overexpressing CD109; CD109 overexpression attenuates TGF-β1 signaling and enhances EGF signaling and cell migration/invasion in SK-MG-1 but not in U251MG or MG178 cells; the secreted N-terminal CD109 fragment (hyperglycosylated in SK-MG-1) inhibits TGF-β1 signaling via paracrine effect but does not affect EGF signaling. |
Co-immunoprecipitation of CD109 with EGFR, conditioned medium experiments, TGF-β and EGF signaling assays, migration/invasion assays |
Biochemical and biophysical research communications |
Medium |
25724945
|
| 2016 |
CD109 overexpression in mouse epidermis differentially regulates TGF-β receptor signaling: it enhances ALK1-Smad1/5 signaling while decreasing ALK5-Smad2/3 signaling; ALK1 co-localizes with CD109 in keratinocytes; CD109-overexpressing epidermal cells reduce ECM production in adjacent skin fibroblasts via a paracrine mechanism. |
CD109 transgenic mice, immunofluorescence co-localization of ALK1 and CD109, western blotting for pSmad1/5 and pSmad2/3, conditioned medium from isolated keratinocytes/epidermal explants applied to fibroblasts |
The Journal of investigative dermatology |
Medium |
27866969
|
| 2017 |
CD109 drives lung cancer metastasis through activation of JAK-STAT3 signaling; CD109 promotes a metastatic transcriptional state in lung adenocarcinoma cells, and pharmacological targeting of the JAK-STAT3 pathway blocks CD109-driven metastasis. |
Tumor barcoding in mouse lung adenocarcinoma model, in vivo small-scale screening, genomic approaches, JAK inhibitor treatment |
Nature medicine |
High |
28191885
|
| 2018 |
Upon ER stress, GRP78 translocates to the cell surface where it binds CD109 and acts in concert with CD109 to block TGF-β signaling by routing TGF-β receptor to the caveolae, thereby disrupting Smad2 activation; the upstream mechanism involves IRE1α-triggered SRC activation, ASAP1 phosphorylation, and suppression of retrograde transport. |
Co-immunoprecipitation of GRP78 with CD109, immunofluorescence localization, Smad2 activation assays, ER stress induction, SRC inhibition, dominant-negative and knockdown experiments |
Proceedings of the National Academy of Sciences of the United States of America |
High |
29654145
|
| 2018 |
CD109 deficiency in mice induces a high-turnover osteoporosis-like phenotype in vivo, with reduced bone volume, increased bone turnover markers (NTX collagen, alkaline phosphatase), demonstrating a role for CD109 in bone metabolism. |
CD109 knockout mice, micro-computed tomography, bone histomorphometry, serum bone turnover marker measurements |
Genes to cells |
Medium |
29767469
|
| 2019 |
CD109 regulates the NF-κB signaling pathway in rheumatoid arthritis fibroblast-like synoviocytes; CD109 silencing or neutralizing antibody reduces proinflammatory factor production, cell migration, invasion, chemoattraction, and osteoclast differentiation in RA FLSs; CD109-deficient mice are protected against collagen-induced arthritis. |
CD109 siRNA knockdown, neutralizing anti-CD109 antibody in RA FLS in vitro, CD109 knockout mice in CIA model, cytokine assays, migration/invasion assays |
Annals of the rheumatic diseases |
High |
31455659
|
| 2019 |
CD109 genetic deletion in mice leads to spontaneous epidermal hyperplasia, aberrant accumulation of dermal γδ17 T cells, and enhanced susceptibility to psoriasiform inflammation; CD109 restrains γδ17 cell activation in a cell-extrinsic manner by maintaining skin barrier integrity; γδ17 activation requires IL-23 signals and is reversed by microbiota depletion. |
CD109 knockout mice, flow cytometry, IL-23 blockade, antibiotic-mediated microbiota depletion, skin inflammation models |
Cell reports |
High |
31597099
|
| 2019 |
CD109 CRISPR/Cas9 knockout in SCC cells represses epithelial traits and promotes EMT (elevated mesenchymal markers); recombinant CD109 protein rescues epithelial traits in KO cells; CD109 loss dysregulates 15 signaling pathways including TGF-β; CD109 levels inversely correlate with TGF-β activation in human oral SCC tumors. |
CRISPR/Cas9 CD109 knockout, recombinant CD109 protein rescue, microarray gene expression, KEGG pathway analysis, immunohistochemistry of 52 human oral SCC tumors |
Scientific reports |
Medium |
31695056
|
| 2020 |
CD109 associates with EGFR and regulates AKT/mTOR signaling; CD109 inhibition decreases EGFR phosphorylation and diminishes EGF-elicited AKT/mTOR activation, sensitizing lung adenocarcinoma cells to EGFR inhibitors. |
Co-immunoprecipitation of CD109 with EGFR, CD109 knockdown, EGFR phosphorylation assays, AKT/mTOR signaling assays, EGFR inhibitor sensitivity assays |
Cancer science |
Medium |
32133706
|
| 2020 |
CD109 promotes stromal invasion of lung adenocarcinoma in vivo; CD109-deficient lung adenocarcinoma mouse model shows significantly reduced stromal invasive lesions; CD109 interacts with LTBP1 (identified by mass spectrometry and confirmed by co-immunoprecipitation), and increased CD109 expression enhances stromal TGF-β activation in the presence of LTBP1. |
CD109-deficient genetically engineered lung adenocarcinoma mouse model, mass spectrometry identification of CD109-interacting proteins, co-immunoprecipitation of CD109 with LTBP1, TGF-β activation assays |
Cancer science |
High |
33007133
|
| 2020 |
CD109 promotes EMT and stemness in lung adenocarcinoma via activation of YAP (Hippo pathway); CD109 elevation correlates with YAP signature; YAP activation participates in CD109-elicited EMT gene expression and tumor invasiveness. |
CD109 overexpression and knockdown in lung adenocarcinoma cells, YAP pathway activity assays, EMT marker analysis, invasion assays |
Cells |
Medium |
33375719
|
| 2020 |
CD109 mediates cervical squamous cell carcinoma tumorigenicity and aggressiveness via EGFR-mediated STAT3 phosphorylation; CD109 knockdown (siRNA) or CRISPR/Cas9 knockout reverses in vitro and in vivo tumorigenic and aggressive properties. |
siRNA knockdown, CRISPR/Cas9 knockout, EGFR and STAT3 phosphorylation assays, xenograft models, sphere-forming and colony assays |
British journal of cancer |
Medium |
32507856
|
| 2021 |
CD109 physically interacts with glycoprotein 130 (GP130) to promote IL-6/STAT3 pathway activation in glioblastoma stem cells; genetic depletion of CD109 abolishes stemness/self-renewal and impairs tumorigenicity, causing phenotypic shift to astrocytic-like differentiation; CD109/STAT3 axis mediates chemoresistance. |
Co-immunoprecipitation of CD109 with GP130, genetic CD109 depletion, STAT3 activation assays, sphere formation, xenograft tumorigenicity, pharmacological STAT3 inhibition |
JCI insight |
High |
33986188
|
| 2021 |
CD109 (GPI-anchored protein on hematopoietic stem/progenitor cells) suppresses TGF-β signaling in HSPCs; CD109 knockout/knockdown in TF-1 cells and primary cord blood MEPs leads to erythroid differentiation upon TGF-β stimulation; in PNH patients, CD109-negative (GPI-deficient) MEPs show greater CD36 expression (erythroid commitment marker) than CD109-positive MEPs. |
CD109 knockout and knockdown in TF-1 cells and primary HSPCs, erythroid differentiation assays, flow cytometry of PNH patient peripheral blood MEPs |
Leukemia |
Medium |
34743190
|
| 2021 |
Meprin β cleaves CD109 at the cell surface within its bait region, releasing soluble CD109 fragments; proteolytic cleavage by meprin β reduces the amount of full-length CD109 sorted to extracellular vesicles; the C-terminal region of CD109 is required for its association with exosomes. |
Meprin β cleavage assay in vitro and in cells, western blotting of CD109 fragments, homology modeling of CD109 structure, single-particle analysis, extracellular vesicle isolation and quantification |
Frontiers in cell and developmental biology |
Medium |
33738281
|
| 2015 |
CD109 is a component of exosomes secreted from cultured cells; the C-terminal region of CD109 is required for its incorporation into exosomes (truncated CD109 lacking the C-terminal region is not associated with exosomes). |
FLAG-tagged CD109 immunoprecipitation from conditioned medium, mass spectrometry identification of co-precipitated exosomal proteins, immuno-electron microscopy, truncation mutant analysis |
Biochemical and biophysical research communications |
Medium |
26707640
|
| 2022 |
CD109 forms a heteromeric complex with EGFR at the cell surface, stabilizing EGFR protein levels and promoting EGFR/AKT signaling in vulvar and hypopharyngeal SCC cells; CD109 is required for in vivo tumorigenicity and for maintaining epithelial morphology and stemness; cell-surface localization of CD109 is required for its pro-tumorigenic effects. |
Co-immunoprecipitation and immunofluorescence co-localization of CD109-EGFR, CD109 knockdown/knockout, mRNA and protein level analysis of EGFR, AKT phosphorylation, xenograft tumor models, spheroid formation |
Cancers |
Medium |
35954339
|
| 2024 |
Proteolytic cleavage of CD109 bait region by diverse proteases induces a conformational change that activates the CD109 thioester; activated CD109 conjugates proteases via its thioester and decreases their activity toward protein substrates, demonstrating CD109 is a protease inhibitor; the GPI-anchored MG8 domain dissociates during conformational change, enabling CD109 release from the cell surface by proteases rather than unspecific shedding. |
In vitro protease cleavage assays with diverse proteases, thioester activation assays, protease conjugation assays, activity inhibition assays, protease-induced membrane release experiments |
The FEBS journal |
High |
38587194
|
| 2025 |
Three cryo-EM structures of CD109 in native, protease-activated, and methylamine-activated conformations reveal the structural mechanism of protease inhibition: protease cleavage of the bait region triggers a conformational change similar to A2ML1 (suggesting shared mechanism); CD109 glycans contribute to protease inhibition; deglycosylation enhances substrate access but does not affect chymotrypsin conjugation. |
Cryo-electron microscopy structure determination of three CD109 conformations, deglycosylation experiments, chymotrypsin conjugation assays |
Cell reports |
High |
40482031
|
| 2025 |
Tumor-derived soluble CD109 (sCD109) upregulates CD73 mRNA transcription in macrophages by activating the FcγRI/SYK/NF-κB signaling pathway; sCD109 is internalized into macrophage cytoplasm and inhibits CD73 protein degradation by binding E3 ligase TRIM21, competing with CD73 for its binding site; this promotes enrichment of CD73+ tumor-associated macrophages that inhibit T-cell responses. |
Proteomic analysis, single-cell transcriptomics, mass spectrometry, NF-κB pathway activation assays, Co-IP of sCD109 with TRIM21 and CD73, CD73 protein stability assays, T-cell functional assays |
Journal of hepatology |
Medium |
40220905
|
| 2023 |
CD109 expression is required on conventional dendritic cells (cDC2s) for airway hyperreactivity and eosinophilic inflammation; CD109 is induced in lung cDC2s upon allergic challenge; CD109-deficient cDC2s have elevated RUNX3 expression and impaired ability to drive Th2 cytokine production and Th2 differentiation; adoptive transfer of CD109-deficient DCs fails to reconstitute AHR and eosinophilic inflammation. |
CD109 knockout mice, allergen sensitization models (HDM, OVA), ex vivo DC-T cell co-cultures, adoptive transfer of bone marrow-derived DCs, anti-CD109 monoclonal antibody treatment |
American journal of respiratory cell and molecular biology |
High |
36215676
|
| 2023 |
CD109 inhibits BMP signaling in osteosarcoma: CD109 knockdown enhances SMAD1/5/9 phosphorylation under BMP-2 stimulation and attenuates osteosarcoma cell migration; CD109 expression inversely correlates with pSMAD1/5/9 in human osteosarcoma tissue; no association found between CD109 and TGF-β signaling in osteosarcoma cells. |
CD109 siRNA knockdown, BMP-2 stimulation with pSMAD1/5/9 western blotting, in vitro wound healing assay, immunohistochemistry of human osteosarcoma tissue |
Pathology, research and practice |
Medium |
37030166
|
| 2024 |
Under mechanical force, CD109 expression on PDLSCs is upregulated (via miR-340-5p repression); CD109 suppresses osteogenesis of PDLSCs through the JAK/STAT3 signaling pathway and promotes osteoclast formation and M1 macrophage polarization through paracrine mechanisms; CD109 knockdown in vivo increases osteogenic activity and decreases osteoclast numbers and tooth movement. |
Mechanical force stimulation in vitro and rat tooth movement model in vivo, JAK/STAT3 pathway analysis, lentiviral shRNA injection, miR-340-5p functional studies, co-culture paracrine assays |
Stem cells translational medicine |
Medium |
38885217
|
| 2025 |
CD109 interacts with and stabilizes IL-6 receptor alpha (IL6Rα) expression; CD109 promotes IL-6/STAT3/NRF2/SOD1/HO1 pathway activation in oral and vulvar SCC cells; CD109 loss attenuates this pathway, reducing cancer stemness and antioxidant protein expression. |
Co-immunoprecipitation of CD109 with IL6Rα, immunofluorescence and FACS co-localization, IL6Rα protein stability assays, STAT3/NRF2 pathway assays, CD109 knockdown/knockout, spheroid formation, multi-omic clinical validation |
Experimental hematology & oncology |
Medium |
40317079
|
| 1998 |
CD109 (a GPI-anchored protein on platelets) carries ABH blood group antigens; anti-A monoclonal antibodies react with CD109 on immunoprecipitation/immunoblotting; phosphatidylinositol-specific phospholipase C treatment releases a 175 kDa GPI-anchored protein (CD109) expressing blood group determinants. |
Immunoprecipitation/immunoblotting with monoclonal antibodies against glycoproteins and blood group antigens, PI-PLC cleavage and Western blot |
The Journal of laboratory and clinical medicine |
Medium |
9708575
|
| 2016 |
Reduced CD109 expression in hepatocellular carcinoma tumor-associated endothelial cells promotes tumor progression through paracrine IL-8; CD109 knockdown in HUVEC activates TGF-β/Akt/NF-κB pathway, upregulating IL-8 secretion, which in turn promotes hepatoma cell proliferation, migration, and invasion; co-implantation with CD109 knockdown HUVEC accelerates tumor growth and metastasis in mice. |
CD109 knockdown in HUVEC, cytokine antibody array screening, IL-8 validation, TGF-β/Akt/NF-κB pathway analysis, co-culture assays, xenograft co-implantation |
Oncotarget |
Medium |
27121053
|
| 2023 |
αv integrins in vascular smooth muscle cells act in concert with CD109 to regulate TGF-β signaling; αv SMKO mice show prolonged CD109 expression; CD109 overexpression in cultured VSMCs phenocopies αv integrin knockdown (attenuating collagen expression, TGF-β activation, and Smad2/3 signaling); CD109 and TGF-β receptor are co-internalized in early endosomes. |
αv integrin conditional knockout mice, transcriptomic analysis, CD109 overexpression in mouse and human VSMCs, Smad2/3 signaling assays, collagen expression assays, endosomal co-localization |
European heart journal open |
Medium |
36909248
|
| 2024 |
CD109 attenuates bleomycin-induced pulmonary fibrosis by inhibiting TGF-β signaling; CD109 transgenic mice show attenuated fibrosis; recombinant CD109 protein inhibits TGF-β signaling and decreases ACTA2 expression in lung fibroblasts in vitro and reduces pulmonary fibrosis in vivo upon administration. |
CD109 transgenic and CD109-/- mice in bleomycin model, recombinant CD109 protein in vitro signaling assays, in vivo recombinant protein administration, ACTA2 and TGF-β signaling readouts |
Journal of immunology |
High |
38334455
|