{"gene":"TLL1","run_date":"2026-06-10T10:51:55","timeline":{"discoveries":[{"year":1999,"finding":"TLL1 (mTLL-1) is an astacin-like metalloprotease expressed specifically in precardiac tissue and endocardium; genetic knockout (Tll1-/-) causes embryonic lethality from cardiac failure with incomplete muscular interventricular septum formation and abnormal heart/aorta positioning, establishing TLL1 as essential for interventricular septum formation in a tissue where Bmp1 is not expressed.","method":"Gene targeting/knockout in ES cells, in situ expression analysis, embryological phenotyping","journal":"Development (Cambridge, England)","confidence":"High","confidence_rationale":"Tier 2 / Strong — clean loss-of-function mouse model with specific cardiac phenotype, expression analysis supporting tissue-specific role, replicated logic with Bmp1 co-expression analysis","pmids":["10331975"],"is_preprint":false},{"year":2003,"finding":"Using Bmp1/Tll1 doubly homozygous null mice, mTLL-1 was demonstrated to be an in vivo procollagen C-proteinase (pCP) providing residual pCP activity observed in Bmp1-/- embryos, and together with BMP-1, is responsible for in vivo cleavage of Chordin (an extracellular BMP-signaling antagonist) in mammals.","method":"Bmp1/Tll1 double knockout mouse embryos, biochemical analysis of pCP activity, proteomics-based substrate identification","journal":"Molecular and cellular biology","confidence":"High","confidence_rationale":"Tier 1-2 / Strong — genetic removal of functional redundancy with double null mice, biochemical in vivo assays for pCP activity, proteomics substrate validation; multiple orthogonal methods in single study","pmids":["12808086"],"is_preprint":false},{"year":2009,"finding":"TLL-1 forms a calcium-ion dependent dimer with monomers stacked side-by-side; truncated TLL-1 molecules with the same shorter structure as BMP-1 are monomers and show improved (higher) activity toward chordin substrate, exceeding both full-length TLL-1 and BMP-1, demonstrating a substrate exclusion mechanism dependent on the non-catalytic domains and dimerization.","method":"Structural and biochemical analysis, truncation mutants, activity assay toward chordin substrate","journal":"FEBS letters","confidence":"Medium","confidence_rationale":"Tier 1 / Weak — in vitro structural and activity data with truncation mutants, single lab, no crystal/cryo-EM structure reported","pmids":["20043912"],"is_preprint":false},{"year":2014,"finding":"Induced postnatal simultaneous ablation of Bmp1 and Tll1 in mice causes osteogenesis imperfecta with spontaneous fractures, osteomalacia, reduced processing of procollagen and dentin matrix protein 1 (DMP1), high bone turnover, and defective osteocyte maturation with decreased sclerostin expression and induced canonical Wnt signaling, demonstrating that TLL1 (together with BMP1) processes procollagen and DMP1 in bone.","method":"Conditional double knockout mouse model (floxed alleles), bone histology, biochemical assays for procollagen processing, immunohistochemistry for DMP1 and sclerostin, Wnt signaling reporters","journal":"Human molecular genetics","confidence":"High","confidence_rationale":"Tier 2 / Strong — conditional double KO mice with multiple orthogonal phenotypic and biochemical readouts, avoids redundancy issues of single KO models","pmids":["24419319"],"is_preprint":false},{"year":2017,"finding":"Conditional double ablation of Bmp1 and Tll1 causes progressive periodontal defects including malformed periodontal ligament, alveolar bone loss, and reduced cellular cementum, accompanied by increased uncleaved procollagen I precursor and reduced DMP1, demonstrating TLL1 and BMP1 are required for procollagen I and DMP1 processing in periodontal homeostasis.","method":"Conditional double knockout mice, histology, immunohistochemistry, molecular analysis of procollagen processing and DMP1 levels, antibiotic rescue experiment","journal":"Journal of dental research","confidence":"High","confidence_rationale":"Tier 2 / Strong — conditional double KO with multiple phenotypic readouts and biochemical substrate analysis; rescue experiment adds mechanistic support","pmids":["28068493"],"is_preprint":false},{"year":2016,"finding":"Inactivation of both Bmp1 and Tll1 in type I collagen-expressing cells causes wider predentin, thinner dentin, disorganized dentinal tubules, reduced dentin sialophosphoprotein (DSPP), and disorganized periodontal ligament with less fibrillin-1, establishing roles for TLL1 in dentin and periodontal ligament development.","method":"Col1a1-Cre driven conditional double knockout, X-ray radiography, histology, immunohistochemistry","journal":"Journal of molecular histology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — clean conditional KO with multiple histological and molecular readouts, single lab","pmids":["28000152"],"is_preprint":false},{"year":2022,"finding":"TLL1 knockdown (shRNA) in intestinal epithelial Caco-2 cells significantly reduced K. pneumoniae adhesion and invasion; TLL1 was found to participate in activation of the TGF-β signaling pathway, and inhibition of this pathway reduced bacterial adhesion/invasion, placing TLL1 upstream of TGF-β signaling in this context.","method":"shRNA knockdown, bacterial invasion/adhesion assays, TGF-β pathway inhibitor (SB431542), transcriptome sequencing","journal":"International journal of medical microbiology : IJMM","confidence":"Medium","confidence_rationale":"Tier 2-3 / Moderate — KD with specific phenotypic readout and pharmacological pathway inhibition, two orthogonal approaches, single lab","pmids":["36087399"],"is_preprint":false},{"year":2025,"finding":"TLL1 promotes prostate cancer cell migration and metastasis by cleaving latent TGF-β1 to activate TGF-β signaling; TLL1 also increases PD-L1 expression via TGF-β signaling activation, and TLL1 depletion enhances anti-PD-1 antibody antitumor efficacy by augmenting CD8+ T cell infiltration. T cell-specific TLL1 overexpression disrupts thymic T cell development and accelerates tumor growth in mice.","method":"TLL1 knockdown/overexpression in prostate cancer cells and mouse models, TGF-β signaling assays, immune cell infiltration analysis, anti-PD-1 treatment experiments","journal":"Oncogene","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — multiple cellular and in vivo models with mechanistic pathway placement, single lab","pmids":["40760092"],"is_preprint":false},{"year":2025,"finding":"A missense mutation p.T253A in the catalytic domain of TLL1 causes autosomal dominant mitral valve prolapse (MVP); the mutant TLL1 protein has 3.4-fold higher enzymatic activity over 12 hours compared to wild-type in HEK293 cell media, indicating a gain-of-function with prolonged half-life of active extracellular TLL1 causing MVP.","method":"Whole exome/genome sequencing with Sanger segregation analysis, in vitro enzymatic activity assay in HEK293-transfected cells comparing wild-type vs mutant TLL1","journal":"The Canadian journal of cardiology","confidence":"Medium","confidence_rationale":"Tier 1-2 / Moderate — enzymatic activity assay directly comparing WT vs mutant in cells, plus human genetic segregation, single lab","pmids":["39880331"],"is_preprint":false},{"year":2026,"finding":"TLL1 protease cleaves SLIT2 (a secreted axon repellent) in cultured cells at a defined TLL1 cleavage site (TLS); TLL1 requires activation by furin/prohormone convertases. CRISPR-edited Slit2ΔTLS mice lacking the TLL1 cleavage site showed reduced fasciculation of DRG axon rootlets and longitudinal projections (without losing dorsal repulsion), and SLIT2-N fragment promoted in vitro DRG axon fasciculation, identifying SLIT2 as a TLL1 substrate and establishing a functional consequence of this cleavage.","method":"Cell-based cleavage assay, CRISPR knock-in mouse model (Slit2ΔTLS), in vivo DRG axon guidance analysis, in vitro axon fasciculation assay","journal":"Development (Cambridge, England)","confidence":"High","confidence_rationale":"Tier 1-2 / Strong — substrate cleavage demonstrated in cells, mechanistic furin activation requirement identified, in vivo CRISPR knock-in model with specific phenotypic readout, in vitro functional validation of SLIT2-N fragment","pmids":["41626796"],"is_preprint":false}],"current_model":"TLL1 is a secreted astacin-like metalloprotease that requires furin-mediated activation and functions extracellularly in multiple contexts: it processes procollagen precursors (procollagen C-proteinase activity), cleaves Chordin to modulate BMP signaling, cleaves SLIT2 to regulate axon fasciculation, and cleaves latent TGF-β1 to activate TGF-β signaling; its activity is regulated by calcium-dependent dimerization via non-catalytic domains, and gain-of-function mutations that increase its half-life cause mitral valve prolapse while loss-of-function disrupts interventricular septum formation, bone, dentin, and periodontal homeostasis."},"narrative":{"mechanistic_narrative":"TLL1 is a secreted astacin-like metalloprotease that acts extracellularly to process precursor and latent substrates governing matrix assembly, morphogenetic signaling, and tissue homeostasis [PMID:10331975, PMID:12808086]. It is essential for heart development: Tll1-null embryos die from cardiac failure with incomplete interventricular septum formation, a role distinct from BMP1, which is not co-expressed in this tissue [PMID:10331975]. Together with BMP1 it provides in vivo procollagen C-proteinase activity and cleaves the BMP antagonist Chordin, linking it to BMP signaling [PMID:12808086], and combined Bmp1/Tll1 ablation impairs processing of procollagen and dentin matrix protein 1 (DMP1), producing osteogenesis imperfecta, defective osteocyte maturation, and periodontal and dentin defects [PMID:24419319, PMID:28068493, PMID:28000152]. TLL1 also cleaves SLIT2 at a defined site to control sensory axon fasciculation, and this proteolysis requires prior furin/prohormone-convertase activation of TLL1 [PMID:41626796]. Beyond matrix substrates, TLL1 activates TGF-β signaling by cleaving latent TGF-β1, promoting prostate cancer migration, metastasis, and PD-L1-mediated immune evasion, and contributing to bacterial adhesion in intestinal epithelium [PMID:36087399, PMID:40760092]. Its activity is tuned by calcium-dependent dimerization through its non-catalytic domains, which restricts substrate access [PMID:20043912]. A gain-of-function catalytic-domain mutation (p.T253A) that prolongs active-enzyme half-life causes autosomal dominant mitral valve prolapse [PMID:39880331].","teleology":[{"year":1999,"claim":"Established TLL1 as a non-redundant developmental metalloprotease by showing it is required for cardiac interventricular septum formation in a tissue where BMP1 is absent, defining a unique in vivo role.","evidence":"Gene knockout in mice with in situ expression analysis and embryological phenotyping","pmids":["10331975"],"confidence":"High","gaps":["Molecular substrate driving the cardiac phenotype not identified","Mechanistic link between protease activity and septum morphogenesis unresolved"]},{"year":2003,"claim":"Resolved the biochemical activity of TLL1 by demonstrating it functions in vivo as a procollagen C-proteinase and, with BMP1, cleaves the BMP antagonist Chordin, placing it in collagen maturation and BMP signaling.","evidence":"Bmp1/Tll1 double-null mouse embryos with biochemical pCP assays and proteomics substrate identification","pmids":["12808086"],"confidence":"High","gaps":["Relative substrate preference of TLL1 vs BMP1 not quantified","Tissue contexts of Chordin cleavage not mapped"]},{"year":2009,"claim":"Explained how TLL1 activity is regulated by showing calcium-dependent side-by-side dimerization through non-catalytic domains imposes a substrate-exclusion mechanism that lowers activity toward Chordin.","evidence":"Structural/biochemical analysis with truncation mutants and chordin activity assays","pmids":["20043912"],"confidence":"Medium","gaps":["No crystal or cryo-EM structure reported","Physiological trigger for dimer-monomer transition unknown","Single-lab in vitro data"]},{"year":2016,"claim":"Extended TLL1 substrate processing to tooth and supporting tissues, showing it is required for dentin and periodontal ligament development via procollagen and DSPP processing.","evidence":"Col1a1-Cre conditional Bmp1/Tll1 double knockout with radiography, histology, immunohistochemistry","pmids":["28000152"],"confidence":"Medium","gaps":["TLL1-specific contribution separate from BMP1 not dissected","Direct DSPP cleavage by TLL1 not shown biochemically"]},{"year":2014,"claim":"Demonstrated a postnatal homeostatic role by showing combined loss causes osteogenesis imperfecta with impaired procollagen and DMP1 processing, defective osteocyte maturation, and altered sclerostin/Wnt signaling.","evidence":"Inducible conditional double knockout with bone histology, biochemical processing assays, and Wnt reporters","pmids":["24419319"],"confidence":"High","gaps":["Whether DMP1 is a direct TLL1 substrate not biochemically isolated","TLL1 versus BMP1 individual contributions not separated"]},{"year":2017,"claim":"Confirmed TLL1's role in periodontal homeostasis through procollagen I and DMP1 processing, with progressive ligament and alveolar bone defects.","evidence":"Conditional double knockout mice with histology, immunohistochemistry, and antibiotic rescue","pmids":["28068493"],"confidence":"High","gaps":["TLL1-specific function not isolated from BMP1","Mechanism connecting substrate processing to bone loss incomplete"]},{"year":2022,"claim":"Placed TLL1 upstream of TGF-β signaling in epithelial cells, linking it to bacterial adhesion and invasion.","evidence":"shRNA knockdown in Caco-2 cells with invasion assays, TGF-β inhibitor, and transcriptome sequencing","pmids":["36087399"],"confidence":"Medium","gaps":["Direct substrate connecting TLL1 to TGF-β activation not identified here","Single cell line and single lab"]},{"year":2025,"claim":"Defined a TGF-β-activating mechanism by showing TLL1 cleaves latent TGF-β1 to drive prostate cancer metastasis and PD-L1-mediated immune evasion.","evidence":"TLL1 knockdown/overexpression in prostate cancer cells and mouse models with TGF-β assays, immune infiltration analysis, and anti-PD-1 treatment","pmids":["40760092"],"confidence":"Medium","gaps":["Direct biochemical cleavage of latent TGF-β1 by purified TLL1 not shown","Generality across cancers untested","Single lab"]},{"year":2025,"claim":"Established a disease mechanism for mitral valve prolapse via a gain-of-function catalytic mutation that prolongs active-enzyme half-life.","evidence":"Whole exome/genome sequencing with segregation and in vitro enzymatic activity comparison of WT vs p.T253A in HEK293 cells","pmids":["39880331"],"confidence":"Medium","gaps":["Tissue substrate driving MVP not identified","In vivo validation of the gain-of-function allele lacking","Single lab"]},{"year":2026,"claim":"Identified SLIT2 as a direct TLL1 substrate and established furin-dependent activation, linking TLL1 cleavage to sensory axon fasciculation.","evidence":"Cell-based cleavage assay, CRISPR Slit2ΔTLS knock-in mice, in vivo DRG axon guidance, and in vitro fasciculation assays","pmids":["41626796"],"confidence":"High","gaps":["Structural basis of SLIT2 recognition not resolved","Other neural contexts of TLL1-SLIT2 cleavage unexplored"]},{"year":null,"claim":"It remains unresolved which direct substrate(s) of TLL1 drive each tissue-specific phenotype and how dimerization, furin activation, and calcium regulation are coordinated in vivo to select among collagen, Chordin, SLIT2, and latent TGF-β1 substrates.","evidence":"","pmids":[],"confidence":"Medium","gaps":["No integrated structural model of substrate selection","Direct biochemical demonstration lacking for DMP1, DSPP, and latent TGF-β1","TLL1-specific versus BMP1-redundant contributions not systematically separated"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0140096","term_label":"catalytic activity, acting on a protein","supporting_discovery_ids":[1,3,7,9]},{"term_id":"GO:0016787","term_label":"hydrolase activity","supporting_discovery_ids":[0,1,8]},{"term_id":"GO:0008092","term_label":"cytoskeletal protein binding","supporting_discovery_ids":[2]}],"localization":[{"term_id":"GO:0005576","term_label":"extracellular region","supporting_discovery_ids":[8,9]},{"term_id":"GO:0031012","term_label":"extracellular matrix","supporting_discovery_ids":[1,3]}],"pathway":[{"term_id":"R-HSA-1474244","term_label":"Extracellular matrix organization","supporting_discovery_ids":[1,3,4,5]},{"term_id":"R-HSA-162582","term_label":"Signal Transduction","supporting_discovery_ids":[1,6,7]},{"term_id":"R-HSA-1266738","term_label":"Developmental Biology","supporting_discovery_ids":[0,9]}],"complexes":[],"partners":["BMP1","CHRD","SLIT2","TGFB1","DMP1","FURIN"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"O43897","full_name":"Tolloid-like protein 1","aliases":[],"length_aa":1013,"mass_kda":114.7,"function":"Protease which processes procollagen C-propeptides, such as chordin, pro-biglycan and pro-lysyl oxidase. Required for the embryonic development. Predominant protease, which in the development, influences dorsal-ventral patterning and skeletogenesis","subcellular_location":"Secreted","url":"https://www.uniprot.org/uniprotkb/O43897/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/TLL1","classification":"Not Classified","n_dependent_lines":0,"n_total_lines":1208,"dependency_fraction":0.0},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/TLL1","total_profiled":1310},"omim":[{"mim_id":"613087","title":"ATRIAL SEPTAL DEFECT 6; ASD6","url":"https://www.omim.org/entry/613087"},{"mim_id":"606743","title":"TOLLOID-LIKE 2; TLL2","url":"https://www.omim.org/entry/606743"},{"mim_id":"606742","title":"TOLLOID-LIKE 1; TLL1","url":"https://www.omim.org/entry/606742"},{"mim_id":"603936","title":"GROWTH/DIFFERENTIATION FACTOR 11; GDF11","url":"https://www.omim.org/entry/603936"},{"mim_id":"603475","title":"CHORDIN; CHRD","url":"https://www.omim.org/entry/603475"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Approved","locations":[{"location":"Vesicles","reliability":"Approved"}],"tissue_specificity":"Tissue enhanced","tissue_distribution":"Detected in many","driving_tissues":[{"tissue":"brain","ntpm":6.4},{"tissue":"placenta","ntpm":6.0}],"url":"https://www.proteinatlas.org/search/TLL1"},"hgnc":{"alias_symbol":[],"prev_symbol":[]},"alphafold":{"accession":"O43897","domains":[{"cath_id":"3.40.390.10","chopping":"150-344","consensus_level":"high","plddt":87.2976,"start":150,"end":344},{"cath_id":"2.60.120.290","chopping":"348-462","consensus_level":"high","plddt":92.1375,"start":348,"end":462},{"cath_id":"2.60.120.290","chopping":"465-575","consensus_level":"high","plddt":92.3433,"start":465,"end":575},{"cath_id":"2.60.120.290","chopping":"619-732","consensus_level":"high","plddt":88.315,"start":619,"end":732},{"cath_id":"2.60.120.290","chopping":"774-887","consensus_level":"high","plddt":90.2358,"start":774,"end":887},{"cath_id":"2.60.120.290","chopping":"890-1005","consensus_level":"high","plddt":88.1438,"start":890,"end":1005}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/O43897","model_url":"https://alphafold.ebi.ac.uk/files/AF-O43897-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-O43897-F1-predicted_aligned_error_v6.png","plddt_mean":80.31},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=TLL1","jax_strain_url":"https://www.jax.org/strain/search?query=TLL1"},"sequence":{"accession":"O43897","fasta_url":"https://rest.uniprot.org/uniprotkb/O43897.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/O43897/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/O43897"}},"corpus_meta":[{"pmid":"10331975","id":"PMC_10331975","title":"The mammalian Tolloid-like 1 gene, Tll1, is necessary for normal septation and positioning of the heart.","date":"1999","source":"Development (Cambridge, England)","url":"https://pubmed.ncbi.nlm.nih.gov/10331975","citation_count":110,"is_preprint":false},{"pmid":"28163062","id":"PMC_28163062","title":"Genome-Wide Association Study Identifies TLL1 Variant Associated With Development of Hepatocellular Carcinoma After Eradication of Hepatitis C Virus Infection.","date":"2017","source":"Gastroenterology","url":"https://pubmed.ncbi.nlm.nih.gov/28163062","citation_count":108,"is_preprint":false},{"pmid":"12808086","id":"PMC_12808086","title":"Use of Bmp1/Tll1 doubly homozygous null mice and proteomics to identify and validate in vivo substrates of bone morphogenetic protein 1/tolloid-like metalloproteinases.","date":"2003","source":"Molecular and cellular biology","url":"https://pubmed.ncbi.nlm.nih.gov/12808086","citation_count":97,"is_preprint":false},{"pmid":"24419319","id":"PMC_24419319","title":"Induced ablation of Bmp1 and Tll1 produces osteogenesis imperfecta in mice.","date":"2014","source":"Human molecular genetics","url":"https://pubmed.ncbi.nlm.nih.gov/24419319","citation_count":58,"is_preprint":false},{"pmid":"34249902","id":"PMC_34249902","title":"PNPLA3 and TLL-1 Polymorphisms as Potential Predictors of Disease Severity in Patients With COVID-19.","date":"2021","source":"Frontiers in cell and developmental biology","url":"https://pubmed.ncbi.nlm.nih.gov/34249902","citation_count":24,"is_preprint":false},{"pmid":"28068493","id":"PMC_28068493","title":"BMP1 and TLL1 Are Required for Maintaining Periodontal Homeostasis.","date":"2017","source":"Journal of dental research","url":"https://pubmed.ncbi.nlm.nih.gov/28068493","citation_count":23,"is_preprint":false},{"pmid":"34071309","id":"PMC_34071309","title":"Association between Interferon-Lambda-3 rs12979860, TLL1 rs17047200 and DDR1 rs4618569 Variant Polymorphisms with the Course and Outcome of SARS-CoV-2 Patients.","date":"2021","source":"Genes","url":"https://pubmed.ncbi.nlm.nih.gov/34071309","citation_count":22,"is_preprint":false},{"pmid":"20043912","id":"PMC_20043912","title":"Structural and functional evidence for a substrate exclusion mechanism in mammalian tolloid like-1 (TLL-1) proteinase.","date":"2009","source":"FEBS letters","url":"https://pubmed.ncbi.nlm.nih.gov/20043912","citation_count":18,"is_preprint":false},{"pmid":"28000152","id":"PMC_28000152","title":"Inactivation of bone morphogenetic protein 1 (Bmp1) and tolloid-like 1 (Tll1) in cells expressing type I collagen leads to dental and periodontal defects in mice.","date":"2016","source":"Journal of molecular histology","url":"https://pubmed.ncbi.nlm.nih.gov/28000152","citation_count":14,"is_preprint":false},{"pmid":"32349377","id":"PMC_32349377","title":"Possible Relevance of PNPLA3 and TLL1 Gene Polymorphisms to the Efficacy of PEG-IFN Therapy for HBV-Infected Patients.","date":"2020","source":"International journal of molecular sciences","url":"https://pubmed.ncbi.nlm.nih.gov/32349377","citation_count":11,"is_preprint":false},{"pmid":"31177595","id":"PMC_31177595","title":"TLL1 variants do not predict hepatocellular carcinoma development in HCV cirrhotic patients treated with direct-acting antivirals.","date":"2019","source":"Journal of viral hepatitis","url":"https://pubmed.ncbi.nlm.nih.gov/31177595","citation_count":11,"is_preprint":false},{"pmid":"36087399","id":"PMC_36087399","title":"Klebsiella pneumoniae activates the TGF-β signaling pathway to adhere to and invade intestinal epithelial cells via enhancing TLL1 expression.","date":"2022","source":"International journal of medical microbiology : IJMM","url":"https://pubmed.ncbi.nlm.nih.gov/36087399","citation_count":10,"is_preprint":false},{"pmid":"33306709","id":"PMC_33306709","title":"Genetic variation in the TLL1 gene is not associated with fibrosis in patients with metabolic associated fatty liver disease.","date":"2020","source":"PloS one","url":"https://pubmed.ncbi.nlm.nih.gov/33306709","citation_count":7,"is_preprint":false},{"pmid":"37981236","id":"PMC_37981236","title":"Assessment of TLL1 variant and risk of hepatocellular carcinoma in Latin Americans and Europeans.","date":"2023","source":"Annals of hepatology","url":"https://pubmed.ncbi.nlm.nih.gov/37981236","citation_count":5,"is_preprint":false},{"pmid":"16369476","id":"PMC_16369476","title":"ASD--lessons on genetic background from transgenic mice with inactive gene encoding metalloprotease, Tolloid-like 1 (TLL1).","date":"2005","source":"Medical science monitor : international medical journal of experimental and clinical research","url":"https://pubmed.ncbi.nlm.nih.gov/16369476","citation_count":4,"is_preprint":false},{"pmid":"25233961","id":"PMC_25233961","title":"Association of TLL1 gene polymorphism (rs1503298, T > C) with coronary heart disease in PREDICT, UDACS and ED cohorts.","date":"2014","source":"Journal of the College of Physicians and Surgeons--Pakistan : JCPSP","url":"https://pubmed.ncbi.nlm.nih.gov/25233961","citation_count":4,"is_preprint":false},{"pmid":"39880331","id":"PMC_39880331","title":"Mitral Valve Prolapse Caused by TLL1 Gain-of-Function Mutation.","date":"2025","source":"The Canadian journal of cardiology","url":"https://pubmed.ncbi.nlm.nih.gov/39880331","citation_count":4,"is_preprint":false},{"pmid":"35567499","id":"PMC_35567499","title":"Deciphering complex rearrangements at the breakpoint of an apparently balanced reciprocal translocation t(4:18)(q31;q11.2)dn and at a cryptic deletion: Further evidence of TLL1 as a causative gene for atrial septal defect.","date":"2022","source":"American journal of medical genetics. Part A","url":"https://pubmed.ncbi.nlm.nih.gov/35567499","citation_count":4,"is_preprint":false},{"pmid":"40760092","id":"PMC_40760092","title":"TLL1 knockdown attenuates prostate cancer progression by enhancing antitumor immunity.","date":"2025","source":"Oncogene","url":"https://pubmed.ncbi.nlm.nih.gov/40760092","citation_count":1,"is_preprint":false},{"pmid":"41626796","id":"PMC_41626796","title":"SLIT2 repellent is cleaved by TLL1 protease and promotes sensory axon fasciculation.","date":"2026","source":"Development (Cambridge, England)","url":"https://pubmed.ncbi.nlm.nih.gov/41626796","citation_count":0,"is_preprint":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":13721,"output_tokens":2763,"usd":0.041304,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":10115,"output_tokens":3488,"usd":0.068888,"stage2_stop_reason":"end_turn"},"total_usd":0.110192,"stage1_batch_id":"msgbatch_017qqVz33Ga63SCDwzb35XPb","stage2_batch_id":"msgbatch_01Scr2Ei9x4HJMiRGxwrmvLK","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 1999,\n      \"finding\": \"TLL1 (mTLL-1) is an astacin-like metalloprotease expressed specifically in precardiac tissue and endocardium; genetic knockout (Tll1-/-) causes embryonic lethality from cardiac failure with incomplete muscular interventricular septum formation and abnormal heart/aorta positioning, establishing TLL1 as essential for interventricular septum formation in a tissue where Bmp1 is not expressed.\",\n      \"method\": \"Gene targeting/knockout in ES cells, in situ expression analysis, embryological phenotyping\",\n      \"journal\": \"Development (Cambridge, England)\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — clean loss-of-function mouse model with specific cardiac phenotype, expression analysis supporting tissue-specific role, replicated logic with Bmp1 co-expression analysis\",\n      \"pmids\": [\"10331975\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2003,\n      \"finding\": \"Using Bmp1/Tll1 doubly homozygous null mice, mTLL-1 was demonstrated to be an in vivo procollagen C-proteinase (pCP) providing residual pCP activity observed in Bmp1-/- embryos, and together with BMP-1, is responsible for in vivo cleavage of Chordin (an extracellular BMP-signaling antagonist) in mammals.\",\n      \"method\": \"Bmp1/Tll1 double knockout mouse embryos, biochemical analysis of pCP activity, proteomics-based substrate identification\",\n      \"journal\": \"Molecular and cellular biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 / Strong — genetic removal of functional redundancy with double null mice, biochemical in vivo assays for pCP activity, proteomics substrate validation; multiple orthogonal methods in single study\",\n      \"pmids\": [\"12808086\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2009,\n      \"finding\": \"TLL-1 forms a calcium-ion dependent dimer with monomers stacked side-by-side; truncated TLL-1 molecules with the same shorter structure as BMP-1 are monomers and show improved (higher) activity toward chordin substrate, exceeding both full-length TLL-1 and BMP-1, demonstrating a substrate exclusion mechanism dependent on the non-catalytic domains and dimerization.\",\n      \"method\": \"Structural and biochemical analysis, truncation mutants, activity assay toward chordin substrate\",\n      \"journal\": \"FEBS letters\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 1 / Weak — in vitro structural and activity data with truncation mutants, single lab, no crystal/cryo-EM structure reported\",\n      \"pmids\": [\"20043912\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"Induced postnatal simultaneous ablation of Bmp1 and Tll1 in mice causes osteogenesis imperfecta with spontaneous fractures, osteomalacia, reduced processing of procollagen and dentin matrix protein 1 (DMP1), high bone turnover, and defective osteocyte maturation with decreased sclerostin expression and induced canonical Wnt signaling, demonstrating that TLL1 (together with BMP1) processes procollagen and DMP1 in bone.\",\n      \"method\": \"Conditional double knockout mouse model (floxed alleles), bone histology, biochemical assays for procollagen processing, immunohistochemistry for DMP1 and sclerostin, Wnt signaling reporters\",\n      \"journal\": \"Human molecular genetics\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — conditional double KO mice with multiple orthogonal phenotypic and biochemical readouts, avoids redundancy issues of single KO models\",\n      \"pmids\": [\"24419319\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"Conditional double ablation of Bmp1 and Tll1 causes progressive periodontal defects including malformed periodontal ligament, alveolar bone loss, and reduced cellular cementum, accompanied by increased uncleaved procollagen I precursor and reduced DMP1, demonstrating TLL1 and BMP1 are required for procollagen I and DMP1 processing in periodontal homeostasis.\",\n      \"method\": \"Conditional double knockout mice, histology, immunohistochemistry, molecular analysis of procollagen processing and DMP1 levels, antibiotic rescue experiment\",\n      \"journal\": \"Journal of dental research\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — conditional double KO with multiple phenotypic readouts and biochemical substrate analysis; rescue experiment adds mechanistic support\",\n      \"pmids\": [\"28068493\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"Inactivation of both Bmp1 and Tll1 in type I collagen-expressing cells causes wider predentin, thinner dentin, disorganized dentinal tubules, reduced dentin sialophosphoprotein (DSPP), and disorganized periodontal ligament with less fibrillin-1, establishing roles for TLL1 in dentin and periodontal ligament development.\",\n      \"method\": \"Col1a1-Cre driven conditional double knockout, X-ray radiography, histology, immunohistochemistry\",\n      \"journal\": \"Journal of molecular histology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — clean conditional KO with multiple histological and molecular readouts, single lab\",\n      \"pmids\": [\"28000152\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"TLL1 knockdown (shRNA) in intestinal epithelial Caco-2 cells significantly reduced K. pneumoniae adhesion and invasion; TLL1 was found to participate in activation of the TGF-β signaling pathway, and inhibition of this pathway reduced bacterial adhesion/invasion, placing TLL1 upstream of TGF-β signaling in this context.\",\n      \"method\": \"shRNA knockdown, bacterial invasion/adhesion assays, TGF-β pathway inhibitor (SB431542), transcriptome sequencing\",\n      \"journal\": \"International journal of medical microbiology : IJMM\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2-3 / Moderate — KD with specific phenotypic readout and pharmacological pathway inhibition, two orthogonal approaches, single lab\",\n      \"pmids\": [\"36087399\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"TLL1 promotes prostate cancer cell migration and metastasis by cleaving latent TGF-β1 to activate TGF-β signaling; TLL1 also increases PD-L1 expression via TGF-β signaling activation, and TLL1 depletion enhances anti-PD-1 antibody antitumor efficacy by augmenting CD8+ T cell infiltration. T cell-specific TLL1 overexpression disrupts thymic T cell development and accelerates tumor growth in mice.\",\n      \"method\": \"TLL1 knockdown/overexpression in prostate cancer cells and mouse models, TGF-β signaling assays, immune cell infiltration analysis, anti-PD-1 treatment experiments\",\n      \"journal\": \"Oncogene\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — multiple cellular and in vivo models with mechanistic pathway placement, single lab\",\n      \"pmids\": [\"40760092\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"A missense mutation p.T253A in the catalytic domain of TLL1 causes autosomal dominant mitral valve prolapse (MVP); the mutant TLL1 protein has 3.4-fold higher enzymatic activity over 12 hours compared to wild-type in HEK293 cell media, indicating a gain-of-function with prolonged half-life of active extracellular TLL1 causing MVP.\",\n      \"method\": \"Whole exome/genome sequencing with Sanger segregation analysis, in vitro enzymatic activity assay in HEK293-transfected cells comparing wild-type vs mutant TLL1\",\n      \"journal\": \"The Canadian journal of cardiology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 1-2 / Moderate — enzymatic activity assay directly comparing WT vs mutant in cells, plus human genetic segregation, single lab\",\n      \"pmids\": [\"39880331\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2026,\n      \"finding\": \"TLL1 protease cleaves SLIT2 (a secreted axon repellent) in cultured cells at a defined TLL1 cleavage site (TLS); TLL1 requires activation by furin/prohormone convertases. CRISPR-edited Slit2ΔTLS mice lacking the TLL1 cleavage site showed reduced fasciculation of DRG axon rootlets and longitudinal projections (without losing dorsal repulsion), and SLIT2-N fragment promoted in vitro DRG axon fasciculation, identifying SLIT2 as a TLL1 substrate and establishing a functional consequence of this cleavage.\",\n      \"method\": \"Cell-based cleavage assay, CRISPR knock-in mouse model (Slit2ΔTLS), in vivo DRG axon guidance analysis, in vitro axon fasciculation assay\",\n      \"journal\": \"Development (Cambridge, England)\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 / Strong — substrate cleavage demonstrated in cells, mechanistic furin activation requirement identified, in vivo CRISPR knock-in model with specific phenotypic readout, in vitro functional validation of SLIT2-N fragment\",\n      \"pmids\": [\"41626796\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"TLL1 is a secreted astacin-like metalloprotease that requires furin-mediated activation and functions extracellularly in multiple contexts: it processes procollagen precursors (procollagen C-proteinase activity), cleaves Chordin to modulate BMP signaling, cleaves SLIT2 to regulate axon fasciculation, and cleaves latent TGF-β1 to activate TGF-β signaling; its activity is regulated by calcium-dependent dimerization via non-catalytic domains, and gain-of-function mutations that increase its half-life cause mitral valve prolapse while loss-of-function disrupts interventricular septum formation, bone, dentin, and periodontal homeostasis.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"TLL1 is a secreted astacin-like metalloprotease that acts extracellularly to process precursor and latent substrates governing matrix assembly, morphogenetic signaling, and tissue homeostasis [#0, #1]. It is essential for heart development: Tll1-null embryos die from cardiac failure with incomplete interventricular septum formation, a role distinct from BMP1, which is not co-expressed in this tissue [#0]. Together with BMP1 it provides in vivo procollagen C-proteinase activity and cleaves the BMP antagonist Chordin, linking it to BMP signaling [#1], and combined Bmp1/Tll1 ablation impairs processing of procollagen and dentin matrix protein 1 (DMP1), producing osteogenesis imperfecta, defective osteocyte maturation, and periodontal and dentin defects [#3, #4, #5]. TLL1 also cleaves SLIT2 at a defined site to control sensory axon fasciculation, and this proteolysis requires prior furin/prohormone-convertase activation of TLL1 [#9]. Beyond matrix substrates, TLL1 activates TGF-\\u03b2 signaling by cleaving latent TGF-\\u03b21, promoting prostate cancer migration, metastasis, and PD-L1-mediated immune evasion, and contributing to bacterial adhesion in intestinal epithelium [#6, #7]. Its activity is tuned by calcium-dependent dimerization through its non-catalytic domains, which restricts substrate access [#2]. A gain-of-function catalytic-domain mutation (p.T253A) that prolongs active-enzyme half-life causes autosomal dominant mitral valve prolapse [#8].\",\n  \"teleology\": [\n    {\n      \"year\": 1999,\n      \"claim\": \"Established TLL1 as a non-redundant developmental metalloprotease by showing it is required for cardiac interventricular septum formation in a tissue where BMP1 is absent, defining a unique in vivo role.\",\n      \"evidence\": \"Gene knockout in mice with in situ expression analysis and embryological phenotyping\",\n      \"pmids\": [\"10331975\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Molecular substrate driving the cardiac phenotype not identified\", \"Mechanistic link between protease activity and septum morphogenesis unresolved\"]\n    },\n    {\n      \"year\": 2003,\n      \"claim\": \"Resolved the biochemical activity of TLL1 by demonstrating it functions in vivo as a procollagen C-proteinase and, with BMP1, cleaves the BMP antagonist Chordin, placing it in collagen maturation and BMP signaling.\",\n      \"evidence\": \"Bmp1/Tll1 double-null mouse embryos with biochemical pCP assays and proteomics substrate identification\",\n      \"pmids\": [\"12808086\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Relative substrate preference of TLL1 vs BMP1 not quantified\", \"Tissue contexts of Chordin cleavage not mapped\"]\n    },\n    {\n      \"year\": 2009,\n      \"claim\": \"Explained how TLL1 activity is regulated by showing calcium-dependent side-by-side dimerization through non-catalytic domains imposes a substrate-exclusion mechanism that lowers activity toward Chordin.\",\n      \"evidence\": \"Structural/biochemical analysis with truncation mutants and chordin activity assays\",\n      \"pmids\": [\"20043912\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No crystal or cryo-EM structure reported\", \"Physiological trigger for dimer-monomer transition unknown\", \"Single-lab in vitro data\"]\n    },\n    {\n      \"year\": 2016,\n      \"claim\": \"Extended TLL1 substrate processing to tooth and supporting tissues, showing it is required for dentin and periodontal ligament development via procollagen and DSPP processing.\",\n      \"evidence\": \"Col1a1-Cre conditional Bmp1/Tll1 double knockout with radiography, histology, immunohistochemistry\",\n      \"pmids\": [\"28000152\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"TLL1-specific contribution separate from BMP1 not dissected\", \"Direct DSPP cleavage by TLL1 not shown biochemically\"]\n    },\n    {\n      \"year\": 2014,\n      \"claim\": \"Demonstrated a postnatal homeostatic role by showing combined loss causes osteogenesis imperfecta with impaired procollagen and DMP1 processing, defective osteocyte maturation, and altered sclerostin/Wnt signaling.\",\n      \"evidence\": \"Inducible conditional double knockout with bone histology, biochemical processing assays, and Wnt reporters\",\n      \"pmids\": [\"24419319\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Whether DMP1 is a direct TLL1 substrate not biochemically isolated\", \"TLL1 versus BMP1 individual contributions not separated\"]\n    },\n    {\n      \"year\": 2017,\n      \"claim\": \"Confirmed TLL1's role in periodontal homeostasis through procollagen I and DMP1 processing, with progressive ligament and alveolar bone defects.\",\n      \"evidence\": \"Conditional double knockout mice with histology, immunohistochemistry, and antibiotic rescue\",\n      \"pmids\": [\"28068493\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"TLL1-specific function not isolated from BMP1\", \"Mechanism connecting substrate processing to bone loss incomplete\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Placed TLL1 upstream of TGF-\\u03b2 signaling in epithelial cells, linking it to bacterial adhesion and invasion.\",\n      \"evidence\": \"shRNA knockdown in Caco-2 cells with invasion assays, TGF-\\u03b2 inhibitor, and transcriptome sequencing\",\n      \"pmids\": [\"36087399\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct substrate connecting TLL1 to TGF-\\u03b2 activation not identified here\", \"Single cell line and single lab\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Defined a TGF-\\u03b2-activating mechanism by showing TLL1 cleaves latent TGF-\\u03b21 to drive prostate cancer metastasis and PD-L1-mediated immune evasion.\",\n      \"evidence\": \"TLL1 knockdown/overexpression in prostate cancer cells and mouse models with TGF-\\u03b2 assays, immune infiltration analysis, and anti-PD-1 treatment\",\n      \"pmids\": [\"40760092\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct biochemical cleavage of latent TGF-\\u03b21 by purified TLL1 not shown\", \"Generality across cancers untested\", \"Single lab\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Established a disease mechanism for mitral valve prolapse via a gain-of-function catalytic mutation that prolongs active-enzyme half-life.\",\n      \"evidence\": \"Whole exome/genome sequencing with segregation and in vitro enzymatic activity comparison of WT vs p.T253A in HEK293 cells\",\n      \"pmids\": [\"39880331\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Tissue substrate driving MVP not identified\", \"In vivo validation of the gain-of-function allele lacking\", \"Single lab\"]\n    },\n    {\n      \"year\": 2026,\n      \"claim\": \"Identified SLIT2 as a direct TLL1 substrate and established furin-dependent activation, linking TLL1 cleavage to sensory axon fasciculation.\",\n      \"evidence\": \"Cell-based cleavage assay, CRISPR Slit2\\u0394TLS knock-in mice, in vivo DRG axon guidance, and in vitro fasciculation assays\",\n      \"pmids\": [\"41626796\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Structural basis of SLIT2 recognition not resolved\", \"Other neural contexts of TLL1-SLIT2 cleavage unexplored\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"It remains unresolved which direct substrate(s) of TLL1 drive each tissue-specific phenotype and how dimerization, furin activation, and calcium regulation are coordinated in vivo to select among collagen, Chordin, SLIT2, and latent TGF-\\u03b21 substrates.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No integrated structural model of substrate selection\", \"Direct biochemical demonstration lacking for DMP1, DSPP, and latent TGF-\\u03b21\", \"TLL1-specific versus BMP1-redundant contributions not systematically separated\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0140096\", \"supporting_discovery_ids\": [1, 3, 7, 9]},\n      {\"term_id\": \"GO:0016787\", \"supporting_discovery_ids\": [0, 1, 8]},\n      {\"term_id\": \"GO:0008092\", \"supporting_discovery_ids\": [2]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005576\", \"supporting_discovery_ids\": [8, 9]},\n      {\"term_id\": \"GO:0031012\", \"supporting_discovery_ids\": [1, 3]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-1474244\", \"supporting_discovery_ids\": [1, 3, 4, 5]},\n      {\"term_id\": \"R-HSA-162582\", \"supporting_discovery_ids\": [1, 6, 7]},\n      {\"term_id\": \"R-HSA-1266738\", \"supporting_discovery_ids\": [0, 9]}\n    ],\n    \"complexes\": [],\n    \"partners\": [\"BMP1\", \"CHRD\", \"SLIT2\", \"TGFB1\", \"DMP1\", \"FURIN\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":6,"faith_total":7,"faith_pct":85.71428571428571}}