{"gene":"MMP15","run_date":"2026-04-28T18:30:28","timeline":{"discoveries":[{"year":1995,"finding":"MMP15 (MT2-MMP) was identified as a membrane-type MMP with a transmembrane domain at the C terminus; it localizes to the cell surface and activates pro-gelatinase A (pro-MMP-2), processing the 68-kDa form through a 64-kDa intermediate to a 62-kDa active form upon transfection into cells.","method":"cDNA cloning from human placenta library, monoclonal antibody recognition of 64-kDa product in transfected cells, gelatin zymography, TIMP-1 fusion localization experiment","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1-2 — original discovery with multiple orthogonal methods (cloning, cell transfection, zymography, cell-surface localization assay), foundational paper with 427 citations","pmids":["7559440"],"is_preprint":false},{"year":2001,"finding":"MT2-MMP activates MMP-2 via a TIMP-2-independent pathway; activation requires MMP-2 hemopexin C-domain-dependent cell surface association of MMP-2 with MT2-MMP, and proceeds through the 68-kDa intermediate without requiring TIMP-2 or concanavalin A.","method":"Stable transfection of hMT2-MMP into TIMP-2-knockout (Timp2-/-) mouse cells; exogenous MMP-2 activation assays; hemopexin C-domain blocking experiments; TIMP binding kinetics (kon measurements); gelatin zymography","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1-2 — reconstitution in TIMP-2-free genetic background with domain-specific blocking, multiple orthogonal methods, 147 citations","pmids":["11584019"],"is_preprint":false},{"year":2006,"finding":"The TIMP-2-independence of MT2-MMP-mediated MMP-2 activation is determined by contributions of both the MT2-MMP catalytic domain (higher propensity to initiate prodomain cleavage without TIMP-2) and the hemopexin C domain (required for the second activation cleavage); MT2-MMP also exhibits weak collagenase activity, and activation is enhanced in type I collagen gels.","method":"Chimeric MT2-MMP/MT1-MMP domain swap constructs expressed in Timp2-/- cells; MMP-2 activation assays; type I collagen gel cultures; TIMP-2/TIMP-3 inhibition assays; trimolecular complex analysis","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1 — domain-swap mutagenesis with reconstitution in genetic knockout background, multiple orthogonal functional assays","pmids":["16825197"],"is_preprint":false},{"year":2009,"finding":"MT2-MMP (MMP15) cooperates with MT1-MMP downstream of Snail1 to drive basement membrane degradation, angiogenesis, and cancer cell intravasation in vivo; siRNA silencing of MT2-MMP completely ablates Snail1-triggered BM invasion and angiogenesis, and these activities cannot be mimicked by secreted MMPs.","method":"siRNA-specific silencing of MT1-MMP and MT2-MMP in cancer cells; in vivo BM invasion, angiogenesis, and intravasation assays; ectopic expression of MT1-MMP and MT2-MMP vs. secreted MMPs","journal":"Proceedings of the National Academy of Sciences of the United States of America","confidence":"High","confidence_rationale":"Tier 2 — clean siRNA KD with specific in vivo phenotypic readouts, replicated across multiple MMP family members as controls, 179 citations","pmids":["19915148"],"is_preprint":false},{"year":2009,"finding":"Epithelial MT2-MMP proteolytically releases collagen IV NC1 domains during submandibular gland branching morphogenesis; NC1 domain release signals via β1 integrin and PI3K-AKT to promote proliferation and morphogenesis, linking MT2-MMP proteolysis to a downstream proliferative signaling cascade.","method":"MT2-MMP siRNA knockdown in submandibular gland organ culture; rescue with recombinant NC1 domains; β1 integrin and PI3K-AKT pathway analysis; HBEGF rescue experiments; proliferation and morphogenesis quantification","journal":"Developmental cell","confidence":"High","confidence_rationale":"Tier 2 — siRNA KD with domain-specific rescue and pathway placement via multiple orthogonal methods, 112 citations","pmids":["19853562"],"is_preprint":false},{"year":2005,"finding":"MMP15 functions as an anti-apoptotic factor in cancer cells; siRNA-mediated knockdown of MMP15 increases sensitivity to Fas-, TRAIL-, and serum starvation-induced apoptosis, while ectopic overexpression confers apoptosis resistance in HeLa S3 and other cancer cell lines.","method":"In vitro apoptosis resistance selection; siRNA knockdown; ectopic overexpression; gene expression profiling; apoptosis assays (Fas, TRAIL, serum starvation)","journal":"The Journal of biological chemistry","confidence":"Medium","confidence_rationale":"Tier 2 — clean KD and OE with specific phenotypic readout but mechanism linking MMP15 proteolytic activity to apoptosis pathway is not resolved","pmids":["16093241"],"is_preprint":false},{"year":2011,"finding":"MMP15 (mmp15) is a direct transcriptional target of Snai1 during endothelial-to-mesenchymal transformation (EMT) in endocardial cushion development; Snai1 overexpression induces mmp15 expression and mesenchymal cell migration, while catalytically active MMP15 promotes cell motility (but not transformation), and MMP15 activity rescues migration defects caused by Snai1 knockdown.","method":"Snai1 knockdown in mice (hypocellular endocardial cushions); Snai1 overexpression in AV canal collagen I gel explants; catalytically active MMP15 treatment; MMP inhibitor experiments; rescue experiments","journal":"Developmental biology","confidence":"Medium","confidence_rationale":"Tier 2 — genetic KD with in vivo phenotype plus rescue with active MMP15; pathway placement via epistasis","pmids":["21920357"],"is_preprint":false},{"year":2016,"finding":"MT2-MMP (MMP15) proteolytically cleaves E-cadherin, generating an 80-kDa N-terminal ectodomain fragment, leading to EMT; catalytically inactive E260A mutant MT2-MMP fails to produce E-cadherin cleavage, restore mesenchymal morphology, or enhance invasion, demonstrating that proteolytic activity is required.","method":"Lentiviral stable transfection of WT and E260A catalytic mutant MT2-MMP; immunoprecipitation of E-cadherin fragments from conditioned medium; MMP inhibitor (GM6001) treatment; siRNA knockdown of endogenous MT2-MMP; chick embryo CAM invasion assay","journal":"Oncotarget","confidence":"High","confidence_rationale":"Tier 1-2 — active-site mutagenesis with substrate identification (E-cadherin cleavage product immunoprecipitated), multiple orthogonal validation methods","pmids":["27374080"],"is_preprint":false},{"year":2017,"finding":"MT2-MMP (MMP15) localizes to the apical domain of polarized epithelial cells where its cytosolic tail interacts with ZO-1; it cleaves E-cadherin at apical junctions, disrupting E-cadherin-mediated cell quiescence, relaxing cortical tension, promoting cell extrusion, and re-sorting Src kinase activity to junctional complexes to drive proliferation.","method":"Co-immunoprecipitation and mass spectrometry (MT2-MMP cytosolic tail–ZO-1 interaction); live imaging/fractionation for apical localization; MT2-MMP loss-of-function in 2D polarized cells, 3D cysts, mouse colonic organoids ex vivo, and intestinal crypts in vivo; Src kinase activity assays","journal":"Journal of cell science","confidence":"High","confidence_rationale":"Tier 1-2 — reciprocal Co-IP/MS for binding partner, subcellular localization linked to functional consequence, loss-of-function in multiple systems including in vivo","pmids":["29061881"],"is_preprint":false},{"year":2016,"finding":"MMP15 expression in mammary gland controls adipocyte fate determination; Mmp15-/- mice retain ductal branching morphogenesis but show differential impairment of thermogenic brown fat formation, while MMP14 controls white fat depot generation.","method":"Global Mmp15 knockout mice; mammary gland morphology assessment; transcriptome profiling of developing mammary glands","journal":"Development (Cambridge, England)","confidence":"Medium","confidence_rationale":"Tier 2 — clean KO with specific in vivo phenotype, but mechanistic pathway from MMP15 to brown fat specification not resolved","pmids":["27633994"],"is_preprint":false},{"year":2011,"finding":"MT2-MMP (MMP15) is a novel hypoxia-responsive gene; HIF-1α directly binds to a specific hypoxia-responsive element (HRE1) in the MT2-MMP promoter to transcriptionally upregulate MT2-MMP under hypoxia, conferring resistance to apoptosis and increased invasiveness.","method":"HRE binding/competition assays; chromatin immunoprecipitation (ChIP) with HIF-1α antibody on MT2-MMP promoter; promoter reporter assays; hypoxia treatment of multiple cancer cell lines; siRNA/OE functional assays","journal":"Molecular carcinogenesis","confidence":"Medium","confidence_rationale":"Tier 2 — ChIP assay directly demonstrating HIF-1α binding to MT2-MMP promoter with functional validation, single lab","pmids":["21751260"],"is_preprint":false},{"year":2019,"finding":"HBXIP activates MMP15 expression through association with the proto-oncogene c-Myc; depletion of c-Myc abolishes HBXIP-mediated MMP-15 upregulation, and MMP15 mediates HBXIP-driven hepatocellular carcinoma cell migration and invasion.","method":"Luciferase reporter assays; chromatin immunoprecipitation (ChIP); siRNA knockdown; in vitro migration/invasion assays; in vivo metastasis model","journal":"Cancer management and research","confidence":"Medium","confidence_rationale":"Tier 2 — ChIP demonstrates c-Myc binding to MMP15 promoter; functional rescue confirms pathway placement; single lab","pmids":["31191014"],"is_preprint":false},{"year":2012,"finding":"MMP-15 co-localizes with endoglin on the syncytiotrophoblast surface but does not cleave endoglin to produce soluble endoglin; concurrent siRNA knockdown of both MMP-14 and MMP-15 yields no further decrease in soluble endoglin compared to MMP-14 knockdown alone.","method":"siRNA knockdown of MMP-15 alone and combined with MMP-14 in HUVECs and BeWo cells; soluble endoglin quantification in conditioned medium; immunolocalization of MMP-15 on syncytiotrophoblast","journal":"PloS one","confidence":"Medium","confidence_rationale":"Tier 2 — clean siRNA KD with quantitative substrate cleavage assay defining negative result; single lab","pmids":["22768148"],"is_preprint":false},{"year":2012,"finding":"MMP-15 is required for invasion of adipose-derived stromal cells (ASCs) through extracellular matrix; siRNA silencing of MMP-15 in obese-donor subcutaneous ASCs significantly reduces invasion through Matrigel and collagen-rich chick chorioallantoic membrane.","method":"siRNA knockdown of MMP-15; Matrigel invasion assay; chick CAM invasion assay; mRNA and protein expression analysis","journal":"Stem cells (Dayton, Ohio)","confidence":"Medium","confidence_rationale":"Tier 2 — clean KD with specific invasion phenotype in two orthogonal ECM barrier systems; single lab","pmids":["22969001"],"is_preprint":false},{"year":2024,"finding":"The m1A demethylase Alkbh3 demethylates Mmp15 mRNA, improving its RNA stability and translational efficiency, which promotes neuronal differentiation and proliferation; Alkbh3 depletion in neural stem cells decreases Mmp15 expression, reducing neurogenesis.","method":"Alkbh3 depletion and overexpression in neural stem cells; m1A modification mapping; Mmp15 mRNA stability and translation assays; in vivo hippocampal neurogenesis and spatial memory assessment","journal":"Cell & bioscience","confidence":"Medium","confidence_rationale":"Tier 2 — epitranscriptomic modification linked to MMP15 mRNA fate with functional in vivo validation; single lab","pmids":["39004750"],"is_preprint":false},{"year":2016,"finding":"TCF-4 functions as a co-activator of NF-κB p65 to promote MMP-15 transcription; TCF-4 potentiates p65 binding to a NF-κB element at -2833/-2824 in the MMP-15 promoter, and MMP-15 overexpression rescues migration defects caused by TCF-4 silencing.","method":"Reporter gene assay; ChIP assay; immunoblotting; siRNA knockdown with rescue by MMP-15 overexpression; xenograft model","journal":"Scientific reports","confidence":"Medium","confidence_rationale":"Tier 2 — ChIP demonstrates TCF-4/p65 binding to MMP15 promoter with functional epistasis rescue; single lab","pmids":["27046058"],"is_preprint":false},{"year":2019,"finding":"LINC00482 promotes MMP15 expression by recruiting the transcription factor FOXA1 to the MMP15 promoter (dual-luciferase reporter assay); MMP15 in turn mediates LINC00482-driven tumor-associated inflammation and angiogenesis (VEGF, NF-κB), and MMP15 overexpression reverses the anti-tumor effects of LINC00482 silencing in vivo.","method":"Dual-luciferase reporter assay; gain- and loss-of-function in bladder cancer cells; in vivo tumor model; VEGF and NF-κB protein quantification","journal":"Aging","confidence":"Low","confidence_rationale":"Tier 3 — reporter assay without direct FOXA1-MMP15 promoter ChIP; single lab; downstream mechanism not fully resolved","pmids":["33323547"],"is_preprint":false},{"year":1997,"finding":"Mouse MT2-MMP (ortholog of human MMP15) activates progelatinase A upon co-transfection into COS-1 cells, confirming conserved MMP-2 activation function of this membrane-type MMP.","method":"cDNA cloning from mouse lung library; co-transfection into COS-1 cells; monoclonal antibody recognition of 70 kDa protein; sequence homology analysis","journal":"FEBS letters","confidence":"Medium","confidence_rationale":"Tier 2 — direct cell transfection assay demonstrating MMP-2 activation; ortholog study corroborating human MMP15 function","pmids":["9037199"],"is_preprint":false},{"year":2019,"finding":"In medaka (teleost ortholog relevant to vertebrate ovulation), Mmp15 expression is regulated by CDK9-dependent phosphorylation of the nuclear progestin receptor (Pgr); phosphorylated Pgr binds the mmp15 promoter to drive LH-induced mmp15 transcription required for follicle rupture and ovulation.","method":"CDK9 inhibitor (CDK9-inhibitor II) and roscovitine treatment of medaka follicles; Pgr phosphorylation analysis; ChIP of Pgr on mmp15 promoter; follicle ovulation assay; CDK9/cyclin I co-expression and association demonstrated","journal":"Cells","confidence":"Medium","confidence_rationale":"Tier 2 — ChIP directly shows Pgr binding to mmp15 promoter with functional ovulation phenotype; teleost ortholog with conserved MMP15 ovulatory role","pmids":["30836650"],"is_preprint":false},{"year":2022,"finding":"MMP15 expression in renal carcinoma cells is regulated by ERK1/2 and p38MAPK signaling; combined siRNA knockdown of ERK or p38MAPK with asiatic acid treatment further reduces MMP15 expression and metastatic activity.","method":"siRNA knockdown of ERK and p38MAPK; MMP-15 protein/mRNA quantification; ELISA for secreted MMP15; in vivo lung metastasis model; pharmacological inhibition with asiatic acid","journal":"Phytomedicine","confidence":"Low","confidence_rationale":"Tier 3 — pathway placement via siRNA epistasis but mechanism of ERK/p38MAPK-to-MMP15 transcriptional regulation not directly established; single lab","pmids":["35316724"],"is_preprint":false}],"current_model":"MMP15 (MT2-MMP) is a cell-surface transmembrane metalloproteinase that activates pro-MMP-2 via a TIMP-2-independent, hemopexin C-domain-dependent mechanism, cleaves extracellular substrates including E-cadherin and collagen IV to drive EMT, BM invasion, branching morphogenesis, and epithelial homeostasis, and is transcriptionally regulated by HIF-1α, Snai1, NF-κB/TCF-4, and CDK9-phosphorylated progesterone receptor, while also functioning as an anti-apoptotic factor whose mRNA stability is controlled by Alkbh3-mediated m1A demethylation."},"narrative":{"teleology":[{"year":1995,"claim":"Identification of MMP15 as a new membrane-anchored MMP that activates pro-MMP-2 at the cell surface established it as the second member of the MT-MMP subfamily with defined substrate specificity.","evidence":"cDNA cloning from human placenta, gelatin zymography, and cell-surface localization in transfected cells","pmids":["7559440"],"confidence":"High","gaps":["Mechanism of pro-MMP-2 intermediate processing steps not resolved","Whether TIMP-2 is required (as for MT1-MMP) was unknown","In vivo substrates beyond MMP-2 uncharacterized"]},{"year":2001,"claim":"Demonstration that MT2-MMP activates MMP-2 independently of TIMP-2 — unlike MT1-MMP — revealed a fundamentally distinct activation mechanism requiring MMP-2 hemopexin C-domain engagement.","evidence":"Reconstitution of MMP-2 activation in Timp2−/− cells; hemopexin C-domain blocking experiments","pmids":["11584019"],"confidence":"High","gaps":["Which structural features of the MT2-MMP catalytic domain confer TIMP-2 independence was unresolved","Stoichiometry and structural basis of the MT2-MMP–MMP-2 complex unknown"]},{"year":2006,"claim":"Domain-swap chimeras between MT2-MMP and MT1-MMP mapped TIMP-2 independence to contributions from both the catalytic domain (first cleavage) and hemopexin C domain (second cleavage), resolving the structural basis of the distinct activation mechanism.","evidence":"Chimeric MT2-MMP/MT1-MMP constructs in Timp2−/− cells with MMP-2 activation assays and collagen gel cultures","pmids":["16825197"],"confidence":"High","gaps":["Atomic-resolution structural model of MT2-MMP–MMP-2 interaction unavailable","Collagenase activity toward native collagen not fully characterized"]},{"year":2005,"claim":"Discovery that MMP15 confers resistance to death-receptor-mediated and serum-starvation-induced apoptosis expanded its role beyond ECM proteolysis to cell survival signaling.","evidence":"siRNA knockdown and ectopic overexpression in cancer cells with Fas, TRAIL, and serum starvation apoptosis assays","pmids":["16093241"],"confidence":"Medium","gaps":["Whether anti-apoptotic effect requires catalytic activity or a non-proteolytic function is unknown","Downstream signaling intermediates linking MMP15 to apoptosis pathways not identified","Single-lab finding without independent replication"]},{"year":2009,"claim":"Parallel studies established MMP15 as an essential effector of Snai1-driven basement membrane invasion and angiogenesis in vivo, and as a protease releasing collagen IV NC1 domains to activate β1-integrin/PI3K-AKT signaling during branching morphogenesis, linking its proteolytic activity to both cancer progression and developmental patterning.","evidence":"siRNA silencing in cancer cells with in vivo BM invasion/intravasation assays; siRNA in submandibular gland organ culture with NC1 rescue and PI3K-AKT pathway analysis","pmids":["19915148","19853562"],"confidence":"High","gaps":["Whether MT2-MMP directly cleaves collagen IV or acts indirectly through MMP-2 at the BM not definitively resolved","Relative contributions of MT1-MMP versus MT2-MMP in different tissue contexts not quantified"]},{"year":2011,"claim":"Identification of HIF-1α binding to the MT2-MMP promoter and Snai1-dependent transcription in endocardial cushion EMT established two key transcriptional regulators, connecting MMP15 expression to hypoxia and developmental EMT programs.","evidence":"ChIP of HIF-1α on MT2-MMP promoter in cancer cells; Snai1 overexpression/knockdown in mouse AV canal explants with MMP15 rescue","pmids":["21751260","21920357"],"confidence":"Medium","gaps":["Whether HIF-1α and Snai1 cooperate or act independently on MMP15 transcription not tested","HIF-1α ChIP from single lab without independent confirmation"]},{"year":2016,"claim":"Three advances defined MMP15's substrate repertoire and transcriptional control: E-cadherin was identified as a direct proteolytic substrate requiring catalytic activity (E260A mutant negative), NF-κB/TCF-4 was shown to co-activate MMP15 transcription, and Mmp15-knockout mice revealed a role in mammary adipocyte fate determination.","evidence":"Active-site mutagenesis with E-cadherin cleavage product IP; ChIP of TCF-4/p65 on MMP15 promoter with rescue; global Mmp15−/− mice with mammary gland phenotyping","pmids":["27374080","27046058","27633994"],"confidence":"High","gaps":["E-cadherin cleavage site not mapped at the amino acid level","Mechanism linking MMP15 to brown fat specification remains unresolved","Whether TCF-4/NF-κB regulation is tissue-specific not determined"]},{"year":2017,"claim":"Discovery that MT2-MMP localizes apically via ZO-1 interaction and cleaves E-cadherin to control cortical tension, cell extrusion, and Src-dependent proliferation established a non-canonical epithelial homeostasis function at adherens junctions.","evidence":"Reciprocal co-IP/MS for ZO-1 interaction; live imaging in polarized cells, 3D cysts, mouse organoids, and intestinal crypts in vivo","pmids":["29061881"],"confidence":"High","gaps":["ZO-1 binding domain on MT2-MMP cytosolic tail not mapped","Whether apical sorting depends on ZO-1 or occurs independently is unresolved","Role of MT2-MMP in intestinal pathology (inflammation, tumorigenesis) not tested"]},{"year":2024,"claim":"Identification of Alkbh3-mediated m1A demethylation of Mmp15 mRNA as a mechanism controlling its stability and translation during neurogenesis introduced an epitranscriptomic layer of MMP15 regulation.","evidence":"Alkbh3 depletion/overexpression in neural stem cells; m1A mapping; mRNA stability assays; in vivo hippocampal neurogenesis and spatial memory assessment","pmids":["39004750"],"confidence":"Medium","gaps":["Specific m1A site(s) on Mmp15 mRNA not mapped","Whether epitranscriptomic regulation of MMP15 operates in non-neural tissues is unknown","Single-lab finding"]},{"year":null,"claim":"The structural basis of MT2-MMP's TIMP-2-independent MMP-2 activation, the identity of the E-cadherin cleavage site, the mechanism linking MMP15 to apoptosis resistance, and its relationship to adipocyte fate specification remain unresolved.","evidence":"","pmids":[],"confidence":"High","gaps":["No crystal or cryo-EM structure of MT2-MMP or MT2-MMP–MMP-2 complex","E-cadherin cleavage site not mapped at residue level","Anti-apoptotic mechanism (catalytic vs. non-catalytic) undetermined","Downstream effectors in brown fat specification unknown"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0140096","term_label":"catalytic activity, acting on a protein","supporting_discovery_ids":[0,1,2,4,7,8]},{"term_id":"GO:0016787","term_label":"hydrolase activity","supporting_discovery_ids":[0,2,7]}],"localization":[{"term_id":"GO:0005886","term_label":"plasma membrane","supporting_discovery_ids":[0,8,12]}],"pathway":[{"term_id":"R-HSA-1474244","term_label":"Extracellular matrix organization","supporting_discovery_ids":[3,4,13]},{"term_id":"R-HSA-1266738","term_label":"Developmental Biology","supporting_discovery_ids":[4,6,9]},{"term_id":"R-HSA-162582","term_label":"Signal Transduction","supporting_discovery_ids":[4,8]},{"term_id":"R-HSA-1500931","term_label":"Cell-Cell communication","supporting_discovery_ids":[7,8]}],"complexes":[],"partners":["MMP2","ZO-1","CDH1","MMP14","SNAI1"],"other_free_text":[]},"mechanistic_narrative":"MMP15 (MT2-MMP) is a cell-surface transmembrane metalloproteinase that activates pro-MMP-2 through a TIMP-2-independent mechanism requiring MMP-2 hemopexin C-domain association and contributions from both its own catalytic and hemopexin C domains [PMID:7559440, PMID:11584019, PMID:16825197]. At the apical surface of polarized epithelia, MMP15 interacts with ZO-1 via its cytosolic tail and proteolytically cleaves E-cadherin, disrupting cell-cell junctions to drive epithelial-to-mesenchymal transition, cell extrusion, and Src-dependent proliferation [PMID:27374080, PMID:29061881]. MMP15 cooperates with MT1-MMP downstream of Snai1 to degrade basement membranes during cancer cell intravasation and angiogenesis, and releases collagen IV NC1 domains during branching morphogenesis to activate β1-integrin/PI3K-AKT proliferative signaling [PMID:19915148, PMID:19853562]. Its transcription is directly regulated by HIF-1α, NF-κB/TCF-4, and Snai1, while its mRNA stability is controlled by Alkbh3-mediated m1A demethylation, and its expression confers resistance to Fas- and TRAIL-induced apoptosis [PMID:21751260, PMID:27046058, PMID:21920357, PMID:39004750, PMID:16093241]."},"prefetch_data":{"uniprot":{"accession":"P51511","full_name":"Matrix metalloproteinase-15","aliases":["Membrane-type matrix metalloproteinase 2","MT-MMP 2","MTMMP2","Membrane-type-2 matrix metalloproteinase","MT2-MMP","MT2MMP","SMCP-2"],"length_aa":669,"mass_kda":75.8,"function":"Endopeptidase that degrades various components of the extracellular matrix. May activate progelatinase A","subcellular_location":"Membrane","url":"https://www.uniprot.org/uniprotkb/P51511/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/MMP15","classification":"Not Classified","n_dependent_lines":4,"n_total_lines":1208,"dependency_fraction":0.0033112582781456954},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/MMP15","total_profiled":1310},"omim":[{"mim_id":"602285","title":"MATRIX METALLOPROTEINASE 17; MMP17","url":"https://www.omim.org/entry/602285"},{"mim_id":"602262","title":"MATRIX METALLOPROTEINASE 16; MMP16","url":"https://www.omim.org/entry/602262"},{"mim_id":"602261","title":"MATRIX METALLOPROTEINASE 15; MMP15","url":"https://www.omim.org/entry/602261"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Approved","locations":[{"location":"Plasma membrane","reliability":"Approved"},{"location":"Cytosol","reliability":"Approved"},{"location":"Nucleoplasm","reliability":"Additional"}],"tissue_specificity":"Tissue enhanced","tissue_distribution":"Detected in many","driving_tissues":[{"tissue":"liver","ntpm":50.7}],"url":"https://www.proteinatlas.org/search/MMP15"},"hgnc":{"alias_symbol":["MT2-MMP","MTMMP2","SMCP-2"],"prev_symbol":[]},"alphafold":{"accession":"P51511","domains":[{"cath_id":"1.10.101","chopping":"53-107","consensus_level":"high","plddt":80.3118,"start":53,"end":107},{"cath_id":"3.40.390.10","chopping":"142-302","consensus_level":"high","plddt":91.3457,"start":142,"end":302},{"cath_id":"2.110.10.10","chopping":"368-556","consensus_level":"high","plddt":90.8077,"start":368,"end":556}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/P51511","model_url":"https://alphafold.ebi.ac.uk/files/AF-P51511-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-P51511-F1-predicted_aligned_error_v6.png","plddt_mean":73.75},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=MMP15","jax_strain_url":"https://www.jax.org/strain/search?query=MMP15"},"sequence":{"accession":"P51511","fasta_url":"https://rest.uniprot.org/uniprotkb/P51511.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/P51511/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/P51511"}},"corpus_meta":[{"pmid":"7559440","id":"PMC_7559440","title":"Identification of the second membrane-type matrix metalloproteinase (MT-MMP-2) gene from a human placenta cDNA library. MT-MMPs form a unique membrane-type subclass in the MMP family.","date":"1995","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/7559440","citation_count":427,"is_preprint":false},{"pmid":"19915148","id":"PMC_19915148","title":"Induction of a MT1-MMP and MT2-MMP-dependent basement membrane transmigration program in cancer cells by Snail1.","date":"2009","source":"Proceedings of the National Academy of Sciences of the United States of America","url":"https://pubmed.ncbi.nlm.nih.gov/19915148","citation_count":179,"is_preprint":false},{"pmid":"11584019","id":"PMC_11584019","title":"Cellular activation of MMP-2 (gelatinase A) by MT2-MMP occurs via a TIMP-2-independent pathway.","date":"2001","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/11584019","citation_count":147,"is_preprint":false},{"pmid":"19853562","id":"PMC_19853562","title":"MT2-MMP-dependent release of collagen IV NC1 domains regulates submandibular gland branching morphogenesis.","date":"2009","source":"Developmental cell","url":"https://pubmed.ncbi.nlm.nih.gov/19853562","citation_count":112,"is_preprint":false},{"pmid":"18093301","id":"PMC_18093301","title":"The first trimester human trophoblast cell line ACH-3P: a novel tool to study autocrine/paracrine regulatory loops of human trophoblast subpopulations--TNF-alpha stimulates MMP15 expression.","date":"2007","source":"BMC developmental biology","url":"https://pubmed.ncbi.nlm.nih.gov/18093301","citation_count":80,"is_preprint":false},{"pmid":"16093241","id":"PMC_16093241","title":"Identification of MMP-15 as an anti-apoptotic factor in cancer cells.","date":"2005","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/16093241","citation_count":68,"is_preprint":false},{"pmid":"16825197","id":"PMC_16825197","title":"TIMP independence of matrix metalloproteinase (MMP)-2 activation by membrane type 2 (MT2)-MMP is determined by contributions of both the MT2-MMP catalytic and hemopexin C domains.","date":"2006","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/16825197","citation_count":58,"is_preprint":false},{"pmid":"30599080","id":"PMC_30599080","title":"LncRNA MAFG-AS1 facilitates the migration and invasion of NSCLC cell via sponging miR-339-5p from MMP15.","date":"2019","source":"Cell biology international","url":"https://pubmed.ncbi.nlm.nih.gov/30599080","citation_count":55,"is_preprint":false},{"pmid":"9037199","id":"PMC_9037199","title":"Isolation of a mouse MT2-MMP gene from a lung cDNA library and identification of its product.","date":"1997","source":"FEBS letters","url":"https://pubmed.ncbi.nlm.nih.gov/9037199","citation_count":53,"is_preprint":false},{"pmid":"21920357","id":"PMC_21920357","title":"Mmp15 is a direct target of Snai1 during endothelial to mesenchymal transformation and endocardial cushion development.","date":"2011","source":"Developmental biology","url":"https://pubmed.ncbi.nlm.nih.gov/21920357","citation_count":45,"is_preprint":false},{"pmid":"23228395","id":"PMC_23228395","title":"Multiple steps of HLA-G in ovarian carcinoma metastasis: alter NK cytotoxicity and induce matrix metalloproteinase-15 (MMP-15) expression.","date":"2012","source":"Human immunology","url":"https://pubmed.ncbi.nlm.nih.gov/23228395","citation_count":42,"is_preprint":false},{"pmid":"22969001","id":"PMC_22969001","title":"Obesity-associated dysregulation of calpastatin and MMP-15 in adipose-derived stromal cells results in their enhanced invasion.","date":"2012","source":"Stem cells (Dayton, Ohio)","url":"https://pubmed.ncbi.nlm.nih.gov/22969001","citation_count":40,"is_preprint":false},{"pmid":"10736239","id":"PMC_10736239","title":"Messenger RNA for membrane-type 2 matrix metalloproteinase, MT2-MMP, is expressed in human placenta of first 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which miRNAs critically contribute to differential roles of Nrf1 and Nrf2 in modulating the epithelial-mesenchymal transformation of hepatocellular carcinoma","date":"2024-12-01","source":"bioRxiv","url":"https://doi.org/10.1101/2024.11.30.626196","citation_count":0,"is_preprint":true}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":23077,"output_tokens":5193,"usd":0.073563},"stage2":{"model":"claude-opus-4-6","input_tokens":8722,"output_tokens":2813,"usd":0.170903},"total_usd":0.244466,"stage1_batch_id":"msgbatch_01Mgbec4vM6c9vXht7JVJzss","stage2_batch_id":"msgbatch_01JkuuH5RB2BdJNsgnhjbC6s","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 1995,\n      \"finding\": \"MMP15 (MT2-MMP) was identified as a membrane-type MMP with a transmembrane domain at the C terminus; it localizes to the cell surface and activates pro-gelatinase A (pro-MMP-2), processing the 68-kDa form through a 64-kDa intermediate to a 62-kDa active form upon transfection into cells.\",\n      \"method\": \"cDNA cloning from human placenta library, monoclonal antibody recognition of 64-kDa product in transfected cells, gelatin zymography, TIMP-1 fusion localization experiment\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 — original discovery with multiple orthogonal methods (cloning, cell transfection, zymography, cell-surface localization assay), foundational paper with 427 citations\",\n      \"pmids\": [\"7559440\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2001,\n      \"finding\": \"MT2-MMP activates MMP-2 via a TIMP-2-independent pathway; activation requires MMP-2 hemopexin C-domain-dependent cell surface association of MMP-2 with MT2-MMP, and proceeds through the 68-kDa intermediate without requiring TIMP-2 or concanavalin A.\",\n      \"method\": \"Stable transfection of hMT2-MMP into TIMP-2-knockout (Timp2-/-) mouse cells; exogenous MMP-2 activation assays; hemopexin C-domain blocking experiments; TIMP binding kinetics (kon measurements); gelatin zymography\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 — reconstitution in TIMP-2-free genetic background with domain-specific blocking, multiple orthogonal methods, 147 citations\",\n      \"pmids\": [\"11584019\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2006,\n      \"finding\": \"The TIMP-2-independence of MT2-MMP-mediated MMP-2 activation is determined by contributions of both the MT2-MMP catalytic domain (higher propensity to initiate prodomain cleavage without TIMP-2) and the hemopexin C domain (required for the second activation cleavage); MT2-MMP also exhibits weak collagenase activity, and activation is enhanced in type I collagen gels.\",\n      \"method\": \"Chimeric MT2-MMP/MT1-MMP domain swap constructs expressed in Timp2-/- cells; MMP-2 activation assays; type I collagen gel cultures; TIMP-2/TIMP-3 inhibition assays; trimolecular complex analysis\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 — domain-swap mutagenesis with reconstitution in genetic knockout background, multiple orthogonal functional assays\",\n      \"pmids\": [\"16825197\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2009,\n      \"finding\": \"MT2-MMP (MMP15) cooperates with MT1-MMP downstream of Snail1 to drive basement membrane degradation, angiogenesis, and cancer cell intravasation in vivo; siRNA silencing of MT2-MMP completely ablates Snail1-triggered BM invasion and angiogenesis, and these activities cannot be mimicked by secreted MMPs.\",\n      \"method\": \"siRNA-specific silencing of MT1-MMP and MT2-MMP in cancer cells; in vivo BM invasion, angiogenesis, and intravasation assays; ectopic expression of MT1-MMP and MT2-MMP vs. secreted MMPs\",\n      \"journal\": \"Proceedings of the National Academy of Sciences of the United States of America\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — clean siRNA KD with specific in vivo phenotypic readouts, replicated across multiple MMP family members as controls, 179 citations\",\n      \"pmids\": [\"19915148\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2009,\n      \"finding\": \"Epithelial MT2-MMP proteolytically releases collagen IV NC1 domains during submandibular gland branching morphogenesis; NC1 domain release signals via β1 integrin and PI3K-AKT to promote proliferation and morphogenesis, linking MT2-MMP proteolysis to a downstream proliferative signaling cascade.\",\n      \"method\": \"MT2-MMP siRNA knockdown in submandibular gland organ culture; rescue with recombinant NC1 domains; β1 integrin and PI3K-AKT pathway analysis; HBEGF rescue experiments; proliferation and morphogenesis quantification\",\n      \"journal\": \"Developmental cell\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — siRNA KD with domain-specific rescue and pathway placement via multiple orthogonal methods, 112 citations\",\n      \"pmids\": [\"19853562\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2005,\n      \"finding\": \"MMP15 functions as an anti-apoptotic factor in cancer cells; siRNA-mediated knockdown of MMP15 increases sensitivity to Fas-, TRAIL-, and serum starvation-induced apoptosis, while ectopic overexpression confers apoptosis resistance in HeLa S3 and other cancer cell lines.\",\n      \"method\": \"In vitro apoptosis resistance selection; siRNA knockdown; ectopic overexpression; gene expression profiling; apoptosis assays (Fas, TRAIL, serum starvation)\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — clean KD and OE with specific phenotypic readout but mechanism linking MMP15 proteolytic activity to apoptosis pathway is not resolved\",\n      \"pmids\": [\"16093241\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2011,\n      \"finding\": \"MMP15 (mmp15) is a direct transcriptional target of Snai1 during endothelial-to-mesenchymal transformation (EMT) in endocardial cushion development; Snai1 overexpression induces mmp15 expression and mesenchymal cell migration, while catalytically active MMP15 promotes cell motility (but not transformation), and MMP15 activity rescues migration defects caused by Snai1 knockdown.\",\n      \"method\": \"Snai1 knockdown in mice (hypocellular endocardial cushions); Snai1 overexpression in AV canal collagen I gel explants; catalytically active MMP15 treatment; MMP inhibitor experiments; rescue experiments\",\n      \"journal\": \"Developmental biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — genetic KD with in vivo phenotype plus rescue with active MMP15; pathway placement via epistasis\",\n      \"pmids\": [\"21920357\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"MT2-MMP (MMP15) proteolytically cleaves E-cadherin, generating an 80-kDa N-terminal ectodomain fragment, leading to EMT; catalytically inactive E260A mutant MT2-MMP fails to produce E-cadherin cleavage, restore mesenchymal morphology, or enhance invasion, demonstrating that proteolytic activity is required.\",\n      \"method\": \"Lentiviral stable transfection of WT and E260A catalytic mutant MT2-MMP; immunoprecipitation of E-cadherin fragments from conditioned medium; MMP inhibitor (GM6001) treatment; siRNA knockdown of endogenous MT2-MMP; chick embryo CAM invasion assay\",\n      \"journal\": \"Oncotarget\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 — active-site mutagenesis with substrate identification (E-cadherin cleavage product immunoprecipitated), multiple orthogonal validation methods\",\n      \"pmids\": [\"27374080\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"MT2-MMP (MMP15) localizes to the apical domain of polarized epithelial cells where its cytosolic tail interacts with ZO-1; it cleaves E-cadherin at apical junctions, disrupting E-cadherin-mediated cell quiescence, relaxing cortical tension, promoting cell extrusion, and re-sorting Src kinase activity to junctional complexes to drive proliferation.\",\n      \"method\": \"Co-immunoprecipitation and mass spectrometry (MT2-MMP cytosolic tail–ZO-1 interaction); live imaging/fractionation for apical localization; MT2-MMP loss-of-function in 2D polarized cells, 3D cysts, mouse colonic organoids ex vivo, and intestinal crypts in vivo; Src kinase activity assays\",\n      \"journal\": \"Journal of cell science\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 — reciprocal Co-IP/MS for binding partner, subcellular localization linked to functional consequence, loss-of-function in multiple systems including in vivo\",\n      \"pmids\": [\"29061881\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"MMP15 expression in mammary gland controls adipocyte fate determination; Mmp15-/- mice retain ductal branching morphogenesis but show differential impairment of thermogenic brown fat formation, while MMP14 controls white fat depot generation.\",\n      \"method\": \"Global Mmp15 knockout mice; mammary gland morphology assessment; transcriptome profiling of developing mammary glands\",\n      \"journal\": \"Development (Cambridge, England)\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — clean KO with specific in vivo phenotype, but mechanistic pathway from MMP15 to brown fat specification not resolved\",\n      \"pmids\": [\"27633994\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2011,\n      \"finding\": \"MT2-MMP (MMP15) is a novel hypoxia-responsive gene; HIF-1α directly binds to a specific hypoxia-responsive element (HRE1) in the MT2-MMP promoter to transcriptionally upregulate MT2-MMP under hypoxia, conferring resistance to apoptosis and increased invasiveness.\",\n      \"method\": \"HRE binding/competition assays; chromatin immunoprecipitation (ChIP) with HIF-1α antibody on MT2-MMP promoter; promoter reporter assays; hypoxia treatment of multiple cancer cell lines; siRNA/OE functional assays\",\n      \"journal\": \"Molecular carcinogenesis\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — ChIP assay directly demonstrating HIF-1α binding to MT2-MMP promoter with functional validation, single lab\",\n      \"pmids\": [\"21751260\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"HBXIP activates MMP15 expression through association with the proto-oncogene c-Myc; depletion of c-Myc abolishes HBXIP-mediated MMP-15 upregulation, and MMP15 mediates HBXIP-driven hepatocellular carcinoma cell migration and invasion.\",\n      \"method\": \"Luciferase reporter assays; chromatin immunoprecipitation (ChIP); siRNA knockdown; in vitro migration/invasion assays; in vivo metastasis model\",\n      \"journal\": \"Cancer management and research\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — ChIP demonstrates c-Myc binding to MMP15 promoter; functional rescue confirms pathway placement; single lab\",\n      \"pmids\": [\"31191014\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"MMP-15 co-localizes with endoglin on the syncytiotrophoblast surface but does not cleave endoglin to produce soluble endoglin; concurrent siRNA knockdown of both MMP-14 and MMP-15 yields no further decrease in soluble endoglin compared to MMP-14 knockdown alone.\",\n      \"method\": \"siRNA knockdown of MMP-15 alone and combined with MMP-14 in HUVECs and BeWo cells; soluble endoglin quantification in conditioned medium; immunolocalization of MMP-15 on syncytiotrophoblast\",\n      \"journal\": \"PloS one\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — clean siRNA KD with quantitative substrate cleavage assay defining negative result; single lab\",\n      \"pmids\": [\"22768148\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"MMP-15 is required for invasion of adipose-derived stromal cells (ASCs) through extracellular matrix; siRNA silencing of MMP-15 in obese-donor subcutaneous ASCs significantly reduces invasion through Matrigel and collagen-rich chick chorioallantoic membrane.\",\n      \"method\": \"siRNA knockdown of MMP-15; Matrigel invasion assay; chick CAM invasion assay; mRNA and protein expression analysis\",\n      \"journal\": \"Stem cells (Dayton, Ohio)\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — clean KD with specific invasion phenotype in two orthogonal ECM barrier systems; single lab\",\n      \"pmids\": [\"22969001\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"The m1A demethylase Alkbh3 demethylates Mmp15 mRNA, improving its RNA stability and translational efficiency, which promotes neuronal differentiation and proliferation; Alkbh3 depletion in neural stem cells decreases Mmp15 expression, reducing neurogenesis.\",\n      \"method\": \"Alkbh3 depletion and overexpression in neural stem cells; m1A modification mapping; Mmp15 mRNA stability and translation assays; in vivo hippocampal neurogenesis and spatial memory assessment\",\n      \"journal\": \"Cell & bioscience\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — epitranscriptomic modification linked to MMP15 mRNA fate with functional in vivo validation; single lab\",\n      \"pmids\": [\"39004750\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"TCF-4 functions as a co-activator of NF-κB p65 to promote MMP-15 transcription; TCF-4 potentiates p65 binding to a NF-κB element at -2833/-2824 in the MMP-15 promoter, and MMP-15 overexpression rescues migration defects caused by TCF-4 silencing.\",\n      \"method\": \"Reporter gene assay; ChIP assay; immunoblotting; siRNA knockdown with rescue by MMP-15 overexpression; xenograft model\",\n      \"journal\": \"Scientific reports\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — ChIP demonstrates TCF-4/p65 binding to MMP15 promoter with functional epistasis rescue; single lab\",\n      \"pmids\": [\"27046058\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"LINC00482 promotes MMP15 expression by recruiting the transcription factor FOXA1 to the MMP15 promoter (dual-luciferase reporter assay); MMP15 in turn mediates LINC00482-driven tumor-associated inflammation and angiogenesis (VEGF, NF-κB), and MMP15 overexpression reverses the anti-tumor effects of LINC00482 silencing in vivo.\",\n      \"method\": \"Dual-luciferase reporter assay; gain- and loss-of-function in bladder cancer cells; in vivo tumor model; VEGF and NF-κB protein quantification\",\n      \"journal\": \"Aging\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 — reporter assay without direct FOXA1-MMP15 promoter ChIP; single lab; downstream mechanism not fully resolved\",\n      \"pmids\": [\"33323547\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1997,\n      \"finding\": \"Mouse MT2-MMP (ortholog of human MMP15) activates progelatinase A upon co-transfection into COS-1 cells, confirming conserved MMP-2 activation function of this membrane-type MMP.\",\n      \"method\": \"cDNA cloning from mouse lung library; co-transfection into COS-1 cells; monoclonal antibody recognition of 70 kDa protein; sequence homology analysis\",\n      \"journal\": \"FEBS letters\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — direct cell transfection assay demonstrating MMP-2 activation; ortholog study corroborating human MMP15 function\",\n      \"pmids\": [\"9037199\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"In medaka (teleost ortholog relevant to vertebrate ovulation), Mmp15 expression is regulated by CDK9-dependent phosphorylation of the nuclear progestin receptor (Pgr); phosphorylated Pgr binds the mmp15 promoter to drive LH-induced mmp15 transcription required for follicle rupture and ovulation.\",\n      \"method\": \"CDK9 inhibitor (CDK9-inhibitor II) and roscovitine treatment of medaka follicles; Pgr phosphorylation analysis; ChIP of Pgr on mmp15 promoter; follicle ovulation assay; CDK9/cyclin I co-expression and association demonstrated\",\n      \"journal\": \"Cells\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — ChIP directly shows Pgr binding to mmp15 promoter with functional ovulation phenotype; teleost ortholog with conserved MMP15 ovulatory role\",\n      \"pmids\": [\"30836650\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"MMP15 expression in renal carcinoma cells is regulated by ERK1/2 and p38MAPK signaling; combined siRNA knockdown of ERK or p38MAPK with asiatic acid treatment further reduces MMP15 expression and metastatic activity.\",\n      \"method\": \"siRNA knockdown of ERK and p38MAPK; MMP-15 protein/mRNA quantification; ELISA for secreted MMP15; in vivo lung metastasis model; pharmacological inhibition with asiatic acid\",\n      \"journal\": \"Phytomedicine\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 — pathway placement via siRNA epistasis but mechanism of ERK/p38MAPK-to-MMP15 transcriptional regulation not directly established; single lab\",\n      \"pmids\": [\"35316724\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"MMP15 (MT2-MMP) is a cell-surface transmembrane metalloproteinase that activates pro-MMP-2 via a TIMP-2-independent, hemopexin C-domain-dependent mechanism, cleaves extracellular substrates including E-cadherin and collagen IV to drive EMT, BM invasion, branching morphogenesis, and epithelial homeostasis, and is transcriptionally regulated by HIF-1α, Snai1, NF-κB/TCF-4, and CDK9-phosphorylated progesterone receptor, while also functioning as an anti-apoptotic factor whose mRNA stability is controlled by Alkbh3-mediated m1A demethylation.\"\n}\n```","stage2_raw":"```json\n{\n  \"mechanistic_narrative\": \"MMP15 (MT2-MMP) is a cell-surface transmembrane metalloproteinase that activates pro-MMP-2 through a TIMP-2-independent mechanism requiring MMP-2 hemopexin C-domain association and contributions from both its own catalytic and hemopexin C domains [PMID:7559440, PMID:11584019, PMID:16825197]. At the apical surface of polarized epithelia, MMP15 interacts with ZO-1 via its cytosolic tail and proteolytically cleaves E-cadherin, disrupting cell-cell junctions to drive epithelial-to-mesenchymal transition, cell extrusion, and Src-dependent proliferation [PMID:27374080, PMID:29061881]. MMP15 cooperates with MT1-MMP downstream of Snai1 to degrade basement membranes during cancer cell intravasation and angiogenesis, and releases collagen IV NC1 domains during branching morphogenesis to activate β1-integrin/PI3K-AKT proliferative signaling [PMID:19915148, PMID:19853562]. Its transcription is directly regulated by HIF-1α, NF-κB/TCF-4, and Snai1, while its mRNA stability is controlled by Alkbh3-mediated m1A demethylation, and its expression confers resistance to Fas- and TRAIL-induced apoptosis [PMID:21751260, PMID:27046058, PMID:21920357, PMID:39004750, PMID:16093241].\",\n  \"teleology\": [\n    {\n      \"year\": 1995,\n      \"claim\": \"Identification of MMP15 as a new membrane-anchored MMP that activates pro-MMP-2 at the cell surface established it as the second member of the MT-MMP subfamily with defined substrate specificity.\",\n      \"evidence\": \"cDNA cloning from human placenta, gelatin zymography, and cell-surface localization in transfected cells\",\n      \"pmids\": [\"7559440\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Mechanism of pro-MMP-2 intermediate processing steps not resolved\", \"Whether TIMP-2 is required (as for MT1-MMP) was unknown\", \"In vivo substrates beyond MMP-2 uncharacterized\"]\n    },\n    {\n      \"year\": 2001,\n      \"claim\": \"Demonstration that MT2-MMP activates MMP-2 independently of TIMP-2 — unlike MT1-MMP — revealed a fundamentally distinct activation mechanism requiring MMP-2 hemopexin C-domain engagement.\",\n      \"evidence\": \"Reconstitution of MMP-2 activation in Timp2−/− cells; hemopexin C-domain blocking experiments\",\n      \"pmids\": [\"11584019\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Which structural features of the MT2-MMP catalytic domain confer TIMP-2 independence was unresolved\", \"Stoichiometry and structural basis of the MT2-MMP–MMP-2 complex unknown\"]\n    },\n    {\n      \"year\": 2006,\n      \"claim\": \"Domain-swap chimeras between MT2-MMP and MT1-MMP mapped TIMP-2 independence to contributions from both the catalytic domain (first cleavage) and hemopexin C domain (second cleavage), resolving the structural basis of the distinct activation mechanism.\",\n      \"evidence\": \"Chimeric MT2-MMP/MT1-MMP constructs in Timp2−/− cells with MMP-2 activation assays and collagen gel cultures\",\n      \"pmids\": [\"16825197\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Atomic-resolution structural model of MT2-MMP–MMP-2 interaction unavailable\", \"Collagenase activity toward native collagen not fully characterized\"]\n    },\n    {\n      \"year\": 2005,\n      \"claim\": \"Discovery that MMP15 confers resistance to death-receptor-mediated and serum-starvation-induced apoptosis expanded its role beyond ECM proteolysis to cell survival signaling.\",\n      \"evidence\": \"siRNA knockdown and ectopic overexpression in cancer cells with Fas, TRAIL, and serum starvation apoptosis assays\",\n      \"pmids\": [\"16093241\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Whether anti-apoptotic effect requires catalytic activity or a non-proteolytic function is unknown\", \"Downstream signaling intermediates linking MMP15 to apoptosis pathways not identified\", \"Single-lab finding without independent replication\"]\n    },\n    {\n      \"year\": 2009,\n      \"claim\": \"Parallel studies established MMP15 as an essential effector of Snai1-driven basement membrane invasion and angiogenesis in vivo, and as a protease releasing collagen IV NC1 domains to activate β1-integrin/PI3K-AKT signaling during branching morphogenesis, linking its proteolytic activity to both cancer progression and developmental patterning.\",\n      \"evidence\": \"siRNA silencing in cancer cells with in vivo BM invasion/intravasation assays; siRNA in submandibular gland organ culture with NC1 rescue and PI3K-AKT pathway analysis\",\n      \"pmids\": [\"19915148\", \"19853562\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Whether MT2-MMP directly cleaves collagen IV or acts indirectly through MMP-2 at the BM not definitively resolved\", \"Relative contributions of MT1-MMP versus MT2-MMP in different tissue contexts not quantified\"]\n    },\n    {\n      \"year\": 2011,\n      \"claim\": \"Identification of HIF-1α binding to the MT2-MMP promoter and Snai1-dependent transcription in endocardial cushion EMT established two key transcriptional regulators, connecting MMP15 expression to hypoxia and developmental EMT programs.\",\n      \"evidence\": \"ChIP of HIF-1α on MT2-MMP promoter in cancer cells; Snai1 overexpression/knockdown in mouse AV canal explants with MMP15 rescue\",\n      \"pmids\": [\"21751260\", \"21920357\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Whether HIF-1α and Snai1 cooperate or act independently on MMP15 transcription not tested\", \"HIF-1α ChIP from single lab without independent confirmation\"]\n    },\n    {\n      \"year\": 2016,\n      \"claim\": \"Three advances defined MMP15's substrate repertoire and transcriptional control: E-cadherin was identified as a direct proteolytic substrate requiring catalytic activity (E260A mutant negative), NF-κB/TCF-4 was shown to co-activate MMP15 transcription, and Mmp15-knockout mice revealed a role in mammary adipocyte fate determination.\",\n      \"evidence\": \"Active-site mutagenesis with E-cadherin cleavage product IP; ChIP of TCF-4/p65 on MMP15 promoter with rescue; global Mmp15−/− mice with mammary gland phenotyping\",\n      \"pmids\": [\"27374080\", \"27046058\", \"27633994\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"E-cadherin cleavage site not mapped at the amino acid level\", \"Mechanism linking MMP15 to brown fat specification remains unresolved\", \"Whether TCF-4/NF-κB regulation is tissue-specific not determined\"]\n    },\n    {\n      \"year\": 2017,\n      \"claim\": \"Discovery that MT2-MMP localizes apically via ZO-1 interaction and cleaves E-cadherin to control cortical tension, cell extrusion, and Src-dependent proliferation established a non-canonical epithelial homeostasis function at adherens junctions.\",\n      \"evidence\": \"Reciprocal co-IP/MS for ZO-1 interaction; live imaging in polarized cells, 3D cysts, mouse organoids, and intestinal crypts in vivo\",\n      \"pmids\": [\"29061881\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"ZO-1 binding domain on MT2-MMP cytosolic tail not mapped\", \"Whether apical sorting depends on ZO-1 or occurs independently is unresolved\", \"Role of MT2-MMP in intestinal pathology (inflammation, tumorigenesis) not tested\"]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Identification of Alkbh3-mediated m1A demethylation of Mmp15 mRNA as a mechanism controlling its stability and translation during neurogenesis introduced an epitranscriptomic layer of MMP15 regulation.\",\n      \"evidence\": \"Alkbh3 depletion/overexpression in neural stem cells; m1A mapping; mRNA stability assays; in vivo hippocampal neurogenesis and spatial memory assessment\",\n      \"pmids\": [\"39004750\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Specific m1A site(s) on Mmp15 mRNA not mapped\", \"Whether epitranscriptomic regulation of MMP15 operates in non-neural tissues is unknown\", \"Single-lab finding\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"The structural basis of MT2-MMP's TIMP-2-independent MMP-2 activation, the identity of the E-cadherin cleavage site, the mechanism linking MMP15 to apoptosis resistance, and its relationship to adipocyte fate specification remain unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"High\",\n      \"gaps\": [\"No crystal or cryo-EM structure of MT2-MMP or MT2-MMP–MMP-2 complex\", \"E-cadherin cleavage site not mapped at residue level\", \"Anti-apoptotic mechanism (catalytic vs. non-catalytic) undetermined\", \"Downstream effectors in brown fat specification unknown\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0140096\", \"supporting_discovery_ids\": [0, 1, 2, 4, 7, 8]},\n      {\"term_id\": \"GO:0016787\", \"supporting_discovery_ids\": [0, 2, 7]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005886\", \"supporting_discovery_ids\": [0, 8, 12]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-1474244\", \"supporting_discovery_ids\": [3, 4, 13]},\n      {\"term_id\": \"R-HSA-1266738\", \"supporting_discovery_ids\": [4, 6, 9]},\n      {\"term_id\": \"R-HSA-162582\", \"supporting_discovery_ids\": [4, 8]},\n      {\"term_id\": \"R-HSA-1500931\", \"supporting_discovery_ids\": [7, 8]}\n    ],\n    \"complexes\": [],\n    \"partners\": [\n      \"MMP2\",\n      \"ZO-1\",\n      \"CDH1\",\n      \"MMP14\",\n      \"SNAI1\"\n    ],\n    \"other_free_text\": []\n  }\n}\n```"}