{"gene":"PCSK6","run_date":"2026-06-10T05:19:53","timeline":{"discoveries":[{"year":1993,"finding":"PC6 (PCSK6) is a subtilisin-like serine endoprotease capable of cleaving precursor proteins at dibasic sites, with a catalytic domain closely related to furin, PC2, PC1/3, PC4, and PACE4, and contains a COOH-terminal Cys-rich region similar to PACE4.","method":"Transfection experiments with cleavage assays; cDNA cloning and sequence analysis","journal":"Journal of biochemistry","confidence":"Medium","confidence_rationale":"Tier 2 / Weak — transfection-based cleavage assay in single lab, single method","pmids":["8468318"],"is_preprint":false},{"year":1993,"finding":"PACE4 (PCSK6) processes pro-von Willebrand factor to its mature form at paired basic residues, with substrate specificity overlapping but not identical to furin; efficient cleavage requires both P4 arginine and P2 lysine, and PACE4 is not inhibited by alpha1-antitrypsin Pittsburgh mutant (unlike furin).","method":"Transient DNA cotransfection assay with pro-vWF substrate; inhibitor studies with alpha1-antitrypsin Pittsburgh mutant","journal":"Biochemistry","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — two orthogonal methods (cotransfection processing assay + inhibitor specificity), single lab","pmids":["8218226"],"is_preprint":false},{"year":1993,"finding":"PACE4 processes pro-von Willebrand factor with cleavage site selectivity similar to PC6A but different from furin.","method":"Recombinant vaccinia virus-based expression with vWF cleavage site mutants","journal":"FEBS letters","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — independent replication of pro-vWF processing by PACE4, with mutant substrate panel","pmids":["8262218"],"is_preprint":false},{"year":1995,"finding":"PACE4 processes prosomatostatin to generate somatostatin-28 (S-28) and somatostatin-14 (S-14) in constitutive secreting LoVo cells, making it a candidate S-28 and S-14 convertase.","method":"Recombinant vaccinia virus coexpression of PACE4 with rat prosomatostatin; HPLC analysis of processed products","journal":"FEBS letters","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — direct in vitro processing assay with product identification, single lab","pmids":["7720860"],"is_preprint":false},{"year":1997,"finding":"PACE4 biosynthesis involves intracellular cleavage of the propeptide (proPACE4 ~106 kDa to PACE4 ~97 kDa) before secretion; PACE4 is not stored in regulated secretory granules; PACE4 enzyme activity is distinctly sensitive to leupeptin inhibition and relatively insensitive to Ca2+ chelators and dithiothreitol, and is not inhibited by the alpha1-antitrypsin Portland variant that potently inhibits furin.","method":"Transfected neuroendocrine and fibroblast cell lines; pulse-chase biosynthesis; enzyme activity assays with various inhibitors","journal":"The Biochemical journal","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — multiple orthogonal methods (biosynthesis, subcellular fractionation, enzyme inhibition), single lab","pmids":["9032441"],"is_preprint":false},{"year":1997,"finding":"PACE4 can activate anthrax toxin protective antigen (PA) at the cell surface, recognizing the sequences RKKR and RAAR (and to a lesser extent KR); PACE4 is present at the exterior of cells and can activate substrates extracellularly.","method":"Furin-deficient CHO cells (FD11) transfected with PACE4; in vitro cleavage assays with iodinated PA and mutant substrates; cytotoxicity assays","journal":"Infection and immunity","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — cell-based and in vitro cleavage assays with substrate mutants, single lab","pmids":["9234799"],"is_preprint":false},{"year":1997,"finding":"PACE4 overexpression in squamous cell carcinoma cells results in enhanced invasiveness and processing of prostromelysin-3 (MMP-11) into its active form, implicating PACE4 in tumor progression via MMP activation.","method":"PACE4 cDNA transfection in mouse SCC cells; invasion assays; prostromelysin-3 processing assays","journal":"Cancer research","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — gain-of-function transfection with defined substrate (prostromelysin-3) processing and functional invasion readout, single lab","pmids":["9393739"],"is_preprint":false},{"year":1998,"finding":"SPC4/PACE4 propeptide cleavage occurs mainly through a unimolecular autocatalytic process in the endoplasmic reticulum (ER); propeptide cleavage is a prerequisite for ER export; the precursor exists as both monomer and dimer, while mature SPC4 is only monomeric.","method":"Site-directed mutagenesis of autocatalytic site; sedimentation velocity analysis; chemical cross-linking; transfected fibroblast cells","journal":"FEBS letters","confidence":"High","confidence_rationale":"Tier 1 / Moderate — site-directed mutagenesis establishing autocatalysis + sedimentation/cross-linking for oligomeric state, multiple orthogonal methods","pmids":["9738469"],"is_preprint":false},{"year":1999,"finding":"PACE4 forms an SDS-stable acyl-intermediate complex (~180 kDa) with alpha1-antitrypsin Portland (alpha1-PDX) both in vivo and in vitro, demonstrating that alpha1-PDX inhibits PACE4. PACE4 is a Ca2+-dependent protease with optimal Ca2+ requirement of 2 mM, highest activity at weakly basic pH, and activity completely inhibited by EDTA and EGTA but not by leupeptin.","method":"In vivo and in vitro complex formation assays; immunological characterization of secreted PACE4; enzyme activity measurements with Ca2+ chelators and inhibitors","journal":"Journal of biochemistry","confidence":"High","confidence_rationale":"Tier 1 / Moderate — direct in vitro and in vivo biochemical characterization with covalent complex demonstration and enzymatic characterization, multiple methods","pmids":["10467177"],"is_preprint":false},{"year":1999,"finding":"PACE4 rescues processing of LDL receptor-related protein and pro-insulin receptor and pro-von Willebrand factor in furin-null RPE.40 cells; PACE4 activity in vitro is Ca2+-dependent and temperature-sensitive (22–37°C) unlike furin; PACE4 does not process Pseudomonas exotoxin A.","method":"Furin-deficient CHO cell complementation; in vitro endoprotease assays; Northern analysis","journal":"The Biochemical journal","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — furin-null cell complementation with multiple substrates and in vitro enzyme characterization, single lab","pmids":["10215603"],"is_preprint":false},{"year":1999,"finding":"PACE4, furin, and PC8 are functionally redundant endogenous proalbumin convertases in HepG2 hepatoma cells, each contributing approximately 30% of proalbumin processing activity.","method":"Antisense RNA stable expression in HepG2 cells; coexpression studies; Northern blot; ribonuclease protection assay","journal":"Journal of biochemistry","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — antisense knockdown with quantified processing readout, coexpression validation, single lab","pmids":["10050053"],"is_preprint":false},{"year":2000,"finding":"SPC4 (PCSK6) is genetically upstream of nodal, pitx2, lefty1, and lefty2 in L/R axis formation; SPC4 acts primarily in the foregut during A/P axis formation as shown by chimeric embryo analysis; SPC4-null embryos develop situs ambiguus and craniofacial defects.","method":"Genetic knockout mouse; gene expression analysis; chimeric embryo analysis; genetic interaction studies with nodal","journal":"Genes & development","confidence":"High","confidence_rationale":"Tier 2 / Strong — knockout mouse phenotype combined with epistasis analysis and chimeric embryo experiments, replicated findings across multiple approaches","pmids":["10809672"],"is_preprint":false},{"year":2002,"finding":"PACE4 overexpression converts non-tumorigenic keratinocytes to invasive malignant cells; processing of stromelysin-3 (MMP-11), MT2-MMP, MMP-2, and MMP-9 is enhanced by PACE4; inhibition of PACE4 with a specific antibody reduced invasion and MMP processing.","method":"Full-length PACE4 cDNA transfection of non-tumorigenic keratinocyte cell lines; in vitro and in vivo invasion assays; antibody inhibition; MMP processing assays","journal":"Carcinogenesis","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — gain-of-function and antibody inhibition with defined substrate processing and functional readout, single lab","pmids":["11960907"],"is_preprint":false},{"year":2005,"finding":"The cysteine-rich domain (CRD) of PACE4 (and PC5A) functions as a cell surface anchor and interacts with TIMP-2; CRD is essential for cell surface tethering and colocalizes/coimmunoprecipitates with full-length and C-terminal domain of TIMP-2; surface-bound PC5A/PACE4 can be displaced by heparin, suramin, heparinases, or excess TIMP-2.","method":"Confocal microscopy; coimmunoprecipitation; biochemical fractionation; heparin displacement; TIMP-2 null fibroblasts with reconstitution; CRD deletion analysis","journal":"Molecular biology of the cell","confidence":"High","confidence_rationale":"Tier 2 / Strong — multiple orthogonal methods (Co-IP, confocal colocalization, domain deletion, null cell reconstitution, displacement experiments) establishing CRD function","pmids":["16135528"],"is_preprint":false},{"year":2005,"finding":"PACE4 overexpression in transgenic mouse basal keratinocytes results in increased processing of MT1-MMP and MT2-MMP, leading to collagenase IV (MMP-2) activation, collagen type IV degradation, basement membrane disruption, and accelerated tumor invasion after chemical carcinogenesis.","method":"Transgenic mice with keratinocyte-targeted PACE4 expression; MT-MMP processing assays; collagenase activity assays; histological analysis; chemical carcinogenesis protocol","journal":"Cancer research","confidence":"High","confidence_rationale":"Tier 2 / Strong — in vivo transgenic model with defined substrate processing (MT1-MMP, MT2-MMP) and functional readout, multiple orthogonal experiments","pmids":["16103082"],"is_preprint":false},{"year":2006,"finding":"Reticulocalbin-3 (RCN-3), a Ca2+-binding protein of the CREC family, transiently associates with the precursor form of PACE4 (proPACE4) but not with mature PACE4; this association occurs in the ER and involves the RXNR target sequences in RCN-3; RCN-3 coexpression increases autoactivation and secretion of PACE4.","method":"Alpha1-antitrypsin inhibitor-based substrate trapping in GH4C1 cells; protein sequence analysis; biosynthetic pulse-chase studies; co-immunoprecipitation; Ca2+ ionophore experiments","journal":"The Biochemical journal","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — Co-IP, substrate trapping, and functional secretion assays, single lab","pmids":["16433634"],"is_preprint":false},{"year":2007,"finding":"PACE4 inhibition in MDA-MB-231 breast cancer cells (via ppPACE4 prosegment or alpha1-PDX) increases MMP-9 activity, reduces TIMP-1 secretion, and enhances cell motility, migration, and collagen invasion; in contrast, furin inhibition decreased MMP-9 activity and reduced these functions, demonstrating opposing roles.","method":"Stable overexpression of PC inhibitors (alpha1-PDX and ppPACE4) in breast cancer cells; MMP activity assays; TIMP-1 ELISA; migration and invasion assays","journal":"Cancer research","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — stable expression with multiple functional readouts and defined substrate pathway, single lab","pmids":["17909005"],"is_preprint":false},{"year":2007,"finding":"E2F1, E2F2, and E2F3 transcription factors upregulate PACE4 expression by binding to two E2F consensus sites (-117/-110 and -86/-79) in the 5'-flanking region of the PACE4 gene; mutation of these sites abolished PACE4 promoter response to E2F1.","method":"Promoter luciferase assays; EMSA (electrophoretic mobility-shift assay); site-directed mutagenesis; mRNA expression analysis in tumor vs. normal cells","journal":"Gene","confidence":"Medium","confidence_rationale":"Tier 1 / Moderate — mutagenesis of transcription factor binding sites confirmed by EMSA and promoter assays, single lab","pmids":["17825503"],"is_preprint":false},{"year":2008,"finding":"Cripto binds the proprotein convertases Furin and PACE4 and localizes Nodal processing at the cell surface; Cripto and uncleaved Nodal associate during secretion; a Cripto-interacting region in the Nodal propeptide potentiates the effect of proteolytic maturation on Nodal signaling; Nodal is exported to the cell surface before entering the TGN/endosomal system.","method":"Co-immunoprecipitation; brefeldin A treatment; density fractionation; antibody uptake experiments; GFP-Flotillin colocalization; coexpression studies","journal":"The EMBO journal","confidence":"High","confidence_rationale":"Tier 2 / Strong — multiple orthogonal methods (Co-IP, subcellular fractionation, live-cell imaging, pharmacological disruption) establishing the Cripto-PACE4 complex and cell surface processing mechanism","pmids":["18772886"],"is_preprint":false},{"year":2008,"finding":"PACE4, along with furin, PC5, and PC7, processes preprohepcidin at the RRRRR59DT site to generate mature hepcidin peptides; this processing was confirmed by site-directed mutagenesis of the cleavage site and in vitro digestion of a synthetic peptide mimicking the cleavage site.","method":"Cell transfection in Huh-7 and LoVo (PC-deficient) cells; site-directed mutagenesis; in vitro peptide digestion assays; furin inhibitor studies","journal":"Gut","confidence":"High","confidence_rationale":"Tier 1 / Moderate — site-directed mutagenesis confirming cleavage site + in vitro peptide cleavage assay + PC-deficient cell complementation, multiple methods single lab","pmids":["18664504"],"is_preprint":false},{"year":2009,"finding":"PACE4 is required for skeletal muscle differentiation in C2C12 cells; PACE4 shRNA suppresses myosin light chain (MLC) expression during myogenesis; this effect is rescued by recombinant mature IGF-II; PACE4 expression is induced by a PI3K-dependent positive feedback loop during differentiation.","method":"shRNA knockdown of PACE4 in C2C12 cells; MLC expression analysis; IGF-II rescue experiment; PI3K inhibitor (LY294002) treatment","journal":"Journal of biochemistry","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — shRNA with rescue experiment and pathway inhibitor confirming mechanism, single lab","pmids":["19520771"],"is_preprint":false},{"year":2011,"finding":"Furin and Pace4 are released by the extraembryonic microenvironment, cleave a membrane-bound reporter substrate in adjacent epiblast cells in a paracrine manner, and activate Nodal to maintain pluripotency; secreted Pace4 (but not Furin) stimulates endoderm induction.","method":"Transgenic reporter substrate live imaging; conditional knockout mouse embryos; paracrine activity assays in embryo culture","journal":"Genes & development","confidence":"High","confidence_rationale":"Tier 2 / Strong — live-imaging of reporter substrate cleavage in vivo, multiple genetic models, and distinct functional outputs for Pace4 vs Furin","pmids":["21896659"],"is_preprint":false},{"year":2012,"finding":"PACE4 inhibition by the Multi-Leu peptide (LLLLRVKR) displays ~20-fold selectivity over furin and significantly reduces proliferation of DU145 and LNCaP prostate cancer cell lines, inducing G0/G1 cell cycle arrest; the peptide must enter cells to inhibit proliferation.","method":"Enzyme kinetic assays with recombinant PACE4 and furin; cell proliferation assays; cell cycle analysis; cell penetration studies","journal":"Journal of medicinal chemistry","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — enzyme kinetics with selectivity quantification and cell-based functional assays, single lab","pmids":["23126600"],"is_preprint":false},{"year":2014,"finding":"PACE4 selectively supports maturation of insulin receptor isoform B (IRB) at the cell surface when furin-dependent intracellular maturation is inefficient; PACE4 does not preferentially process IRA; selective pharmacological inhibition of PACE4 reduces IRA maturation and mitogenic signaling.","method":"Furin-deficient cell transfection; IRB/IRA isoform processing analysis; cell surface receptor assays; PACE4 inhibitor treatment","journal":"The Journal of biological chemistry","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — isoform-selective processing demonstrated in furin-deficient cells with pharmacological validation, single lab","pmids":["25527501"],"is_preprint":false},{"year":2015,"finding":"PCSK6 cleaves and activates corin at the R801 site; PCSK6 siRNA knockdown inhibits corin activation; PCSK6 overexpression enhances corin activation; purified PCSK6 cleaves wild-type corin but not R801A mutant; Pcsk6-knockout mice develop salt-sensitive hypertension with undetectable corin activation and pro-ANP processing activity; CORIN variants associated with hypertension are defective in PCSK6-mediated activation.","method":"siRNA knockdown; overexpression in cultured cells; purified protein cleavage assay with site mutant (R801A); Pcsk6 knockout mice with physiological phenotyping; pro-ANP processing assay","journal":"Nature medicine","confidence":"High","confidence_rationale":"Tier 1 / Strong — in vitro reconstitution with site-mutant corin + in vivo Pcsk6 KO phenotype + human variant validation, multiple orthogonal methods across multiple experimental systems","pmids":["26259032"],"is_preprint":false},{"year":2015,"finding":"PC7, Furin, and Pace4 jointly regulate E-cadherin processing during morula compaction and blastocyst inner cell mass formation; differential inhibition reveals all three PCs are active in overlapping but partially non-overlapping compartments (inner and outer cells).","method":"PC mutant mouse embryos; live imaging of transgenic reporter substrate; pharmacological inhibition with common inhibitor; E-cadherin processing analysis","journal":"The Journal of cell biology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — live-imaging reporter combined with genetic and pharmacological approaches, single lab","pmids":["26416966"],"is_preprint":false},{"year":2016,"finding":"Tbx5 directly regulates Pcsk6 transcription in the posterior second heart field; this was validated by ChIP-qPCR and luciferase reporter assay; Pcsk6 is part of a Tbx5/Osr1/Pcsk6 gene network for atrial septation.","method":"ChIP-qPCR; luciferase reporter assay; RNA-seq; immunohistochemistry; human family genotyping","journal":"Human molecular genetics","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — direct transcription factor binding confirmed by ChIP and reporter assay, single lab","pmids":["26744331"],"is_preprint":false},{"year":2017,"finding":"PACE4 pre-mRNA undergoes DNA methylation-sensitive alternative splicing of its terminal exon, generating an oncogenic C-terminally modified isoform (PACE4-altCT) strongly expressed in prostate cancer; PACE4-altCT displays enhanced autoactivating process, is retained intracellularly (not secreted), and dramatically increases processing of pro-GDF15 as its first identified substrate in prostate cancer.","method":"Alternative splicing analysis; DNA methylation studies; subcellular localization; pro-GDF15 processing assays; expression in multiple cancer cell lines","journal":"Cancer research","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — multiple mechanistic readouts (splicing, localization, substrate processing) in single lab study","pmids":["28993410"],"is_preprint":false},{"year":2017,"finding":"Functional analysis reveals that corin lacking the transmembrane domain is activated by PCSK6 in conditioned medium and under cell-free conditions; cell membrane association is not required for PCSK6 to activate corin; soluble corin and PCSK6 are secreted via different intracellular pathways; heparan sulfate/chondroitin sulfate and heparinase/chondroitinase do not alter corin activation by PCSK6; corin pro-peptide domain is dispensable for PCSK6-mediated activation.","method":"Corin deletion mutant expression in HEK293 cells; cell-free cleavage assay; monensin blockade; immunostaining; glycosaminoglycan treatment and enzyme treatment","journal":"The international journal of biochemistry & cell biology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — domain deletion analysis combined with cell-free assay and pharmacological tools, single lab","pmids":["29180304"],"is_preprint":false},{"year":2020,"finding":"PCSK6 cointeracts with MMP2 and MMP14 in smooth muscle cells (demonstrated by in situ proximity ligation assay); Pcsk6-/- mice show reduced MMP14 activation and decreased intimal hyperplasia after carotid ligation; PCSK6 overexpression increases PDGFBB-induced SMC migration; PCSK6 silencing downregulates contractile SMC markers and increases MMP2 expression.","method":"In situ proximity ligation assay for protein interaction; Pcsk6-/- mouse carotid ligation model; aortic ring SMC outgrowth assay; siRNA knockdown in human SMCs; PCSK6 overexpression migration assays; Affymetrix microarrays","journal":"Circulation research","confidence":"High","confidence_rationale":"Tier 2 / Strong — in situ PLA for protein interaction, in vivo KO phenotype with defined molecular readout (MMP14 activation), and in vitro gain/loss-of-function with multiple orthogonal approaches","pmids":["31893970"],"is_preprint":false},{"year":2020,"finding":"PCSK6 secreted from hypoxic cardiomyocytes activates TGF-β signaling and SMAD3 translocation in fibroblasts; cardiomyocyte-specific AAV9-mediated PCSK6 overexpression in mice increases collagen I and III expression, cardiac fibrosis, and decreases LV function after MI; PCSK6-depleted cardiomyocyte secretome reduces collagen expression in fibroblasts.","method":"Stable isotope labeling secretome analysis; siRNA knockdown; AAV9 cardiomyocyte-specific overexpression in mice; SMAD3 translocation assay; collagen expression analysis; left anterior descending coronary artery ligation model","journal":"Circulation","confidence":"High","confidence_rationale":"Tier 2 / Strong — in vivo AAV9 overexpression with cardiac phenotype + paracrine functional assays + siRNA mechanistic data, multiple orthogonal methods","pmids":["32100557"],"is_preprint":false},{"year":2024,"finding":"PCSK6 cleaves and activates MT5-MMP (η-secretase) by recognizing the RRRNKR sequence in its N-terminal propeptide domain; mutation or knockout of this cleavage motif prevents PCSK6 from interacting with and cleaving MT5-MMP; PCSK6 knockdown reduces amyloidogenic APP processing (Aβ production) and ameliorates hippocampal LTP and spatial memory in AD model mice.","method":"Site-directed mutagenesis of MT5-MMP cleavage motif; Co-IP; N2A cell cleavage assays; AAV-mediated PCSK6 knockdown in APP23/PS45 transgenic mice; LTP electrophysiology; spatial memory testing","journal":"Experimental neurology","confidence":"High","confidence_rationale":"Tier 1 / Moderate — site-directed mutagenesis of cleavage site + Co-IP + in vivo AAV knockdown with cognitive readout, multiple orthogonal methods in single lab","pmids":["38216110"],"is_preprint":false},{"year":2023,"finding":"PCSK6 is identified as a likely antigenic target in membranous nephropathy associated with NSAID use; IgG from affected patients binds to PCSK6 along the glomerular basement membrane, co-localizing with IgG deposits.","method":"Laser microdissection of glomeruli followed by mass spectrometry (MS/MS); protein G immunoprecipitation; immunofluorescence; confocal microscopy; western blot of tissue eluates","journal":"Kidney international","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — multiple orthogonal methods (MS/MS, IP, IHC, WB) establishing antigen identity, but mechanistic role of PCSK6 protease activity not directly tested","pmids":["37119877"],"is_preprint":false},{"year":2001,"finding":"hASH-1 (and MASH-1) transcription factors downregulate PACE4 gene expression by binding to an E-box cluster (E4-E9) in the 5'-flanking region; this effect is specific to PACE4 and does not affect furin, PC5/6, or PC7/8; other neural bHLH factors tested did not affect PACE4 expression.","method":"Luciferase reporter assay; EMSA with hASH-1 binding to E-box cluster; overexpression of hASH-1/MASH-1 in neuroblastoma cell lines; mRNA expression analysis","journal":"The Biochemical journal","confidence":"Medium","confidence_rationale":"Tier 1 / Moderate — mutagenesis/EMSA confirming E-box binding + reporter assay, multiple methods, single lab","pmids":["11736660"],"is_preprint":false},{"year":2002,"finding":"The P4 arginine residue is crucial for PACE4 inhibition by alpha1-antitrypsin variants; an AVRR variant inhibited furin and PC6 but not PACE4; the RVRR variant inhibited both PACE4 and furin but required 600-fold higher concentration to inhibit PC6; these variants form SDS-stable complexes with their respective targets.","method":"In vitro enzyme inhibition assays with fluorogenic substrate; SDS-stable complex formation assays ex vivo; inhibition of pro-complement C3 processing","journal":"Protein engineering","confidence":"Medium","confidence_rationale":"Tier 1 / Moderate — direct in vitro and ex vivo biochemical characterization with defined substrate specificity, multiple inhibitor variants tested, single lab","pmids":["11917148"],"is_preprint":false},{"year":2020,"finding":"Pcsk6-/- mice display increased flow-mediated outward arterial remodeling; absence of PCSK6 increases lumen circumference and reduces medial contractility (decreased active tension) and SMC contractile markers (SMA, MYH11, LMOD1) in response to increased blood flow.","method":"Pcsk6-/- mouse carotid ligation model; ultrasound biomicroscopy; wire myography; immunohistochemistry; transmission electron microscopy","journal":"Cells","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — Pcsk6 KO with defined vascular phenotype measured by multiple methods, single lab","pmids":["32325687"],"is_preprint":false},{"year":2023,"finding":"PCSK6 binds to STAT1 and promotes STAT1 phosphorylation, thereby regulating Th1 cell differentiation; PCSK6 overexpression promotes Th0-to-Th1 conversion, while PCSK6 silencing suppresses it; PCSK6 knockdown in Pcsk6-KO mice ameliorates DSS-induced colitis with decreased Th1 and M1 macrophage proportions.","method":"Co-IP (COPI assay) demonstrating PCSK6-STAT1 binding; Pcsk6 KO mouse DSS colitis model; STAT1 inhibitor studies; in vitro T cell differentiation assays","journal":"Aging","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — Co-IP confirming interaction + in vivo KO phenotype + in vitro functional assay, single lab","pmids":["37211384"],"is_preprint":false}],"current_model":"PCSK6 (PACE4/SPC4) is a subtilisin-like serine endoprotease that undergoes autocatalytic propeptide removal in the ER as a prerequisite for secretion, then acts at the cell surface and extracellularly to cleave diverse precursor proteins at paired basic residue motifs (R-X-X-R), including corin (activating the ANP/blood pressure pathway), Nodal (controlling left-right and anteroposterior axis formation), MT-MMPs (enabling tumor invasion and vascular remodeling), MT5-MMP (promoting amyloidogenic APP processing in Alzheimer's disease), pro-GDF15, prohepcidin, pro-insulin receptor-B, prostromelysin-3, pro-vWF, and anthrax toxin PA; its C-terminal cysteine-rich domain mediates cell surface tethering via TIMP-2 binding; an oncogenic alternatively spliced isoform (PACE4-altCT) is retained intracellularly and drives prostate cancer progression; and PCSK6 modulates SMC contractility and migration via MMP14 activation in vascular remodeling."},"narrative":{"mechanistic_narrative":"PCSK6 (PACE4/SPC4) is a calcium-dependent subtilisin-like serine endoprotease that matures secreted and membrane precursor proteins by cleaving at paired basic (R-X-X-R) motifs, with substrate selectivity overlapping but distinct from furin [PMID:8468318, PMID:8218226, PMID:10467177]. Its biosynthesis requires unimolecular autocatalytic removal of the propeptide in the ER as a prerequisite for export, after which mature enzyme is secreted as a monomer and is not stored in regulated secretory granules [PMID:9032441, PMID:9738469]; the CREC-family Ca2+-binding protein RCN-3 transiently associates with the proform and promotes its autoactivation and secretion [PMID:16433634]. A C-terminal cysteine-rich domain tethers PCSK6 to the cell surface via TIMP-2 binding and heparan-sulfate interactions, positioning it to process substrates extracellularly and at the plasma membrane [PMID:9234799, PMID:16135528]. Through this activity PCSK6 governs developmental axis formation by acting genetically upstream of Nodal/Pitx2/Lefty in left-right and anteroposterior patterning, processing Nodal at the cell surface in complex with Cripto and acting in paracrine fashion to maintain pluripotency and drive endoderm induction [PMID:10809672, PMID:18772886, PMID:21896659]. It activates corin at R801 to drive pro-ANP processing, and its loss produces salt-sensitive hypertension in mice [PMID:26259032]. In the vasculature and heart PCSK6 activates MT-MMPs including MMP14 to control smooth muscle contractility, migration and arterial remodeling, and acts as a hypoxic cardiomyocyte-secreted factor that activates fibroblast TGF-β/SMAD3 signaling to promote cardiac fibrosis [PMID:31893970, PMID:32100557, PMID:32325687]. PCSK6 promotes tumor invasion by processing prostromelysin-3 and MT1/MT2-MMP to activate MMP-2 [PMID:9393739, PMID:16103082], and a DNA-methylation-sensitive alternatively spliced isoform (PACE4-altCT) is retained intracellularly, hyper-autoactivates, processes pro-GDF15, and drives prostate cancer [PMID:28993410]. Additional validated substrates include prohepcidin, the insulin receptor B isoform, pro-von Willebrand factor, and the η-secretase MT5-MMP, whose activation by PCSK6 promotes amyloidogenic APP processing in Alzheimer's disease models [PMID:18664504, PMID:25527501, PMID:8218226, PMID:38216110]. PCSK6 expression is transcriptionally controlled by E2F factors and Tbx5 (activating) and hASH-1 (repressing) [PMID:17825503, PMID:26744331, PMID:11736660].","teleology":[{"year":1993,"claim":"Establishing PCSK6 as a subtilisin-family endoprotease that cleaves precursors at dibasic sites defined its core biochemical identity and substrate logic.","evidence":"cDNA cloning, sequence analysis, and cotransfection cleavage assays of pro-vWF with cleavage-site mutants","pmids":["8468318","8218226","8262218"],"confidence":"Medium","gaps":["Physiological substrate repertoire not defined","No structural basis for substrate selectivity vs furin"]},{"year":1997,"claim":"Defining propeptide cleavage and secretory itinerary showed how PCSK6 is activated and where it acts, distinguishing it from regulated-pathway convertases.","evidence":"Pulse-chase biosynthesis, subcellular fractionation, and cell-surface/extracellular cleavage assays in transfected and furin-deficient cells","pmids":["9032441","9234799"],"confidence":"Medium","gaps":["Mechanism of autocatalysis not yet established","Endogenous physiological substrates unproven"]},{"year":1998,"claim":"Demonstrating unimolecular autocatalytic propeptide removal in the ER as a prerequisite for export resolved the activation mechanism and oligomeric state.","evidence":"Site-directed mutagenesis of the autocatalytic site, sedimentation velocity, and chemical cross-linking in transfected fibroblasts","pmids":["9738469"],"confidence":"High","gaps":["Chaperones/cofactors of folding and autoactivation not identified at this stage"]},{"year":1999,"claim":"Biochemical characterization established PCSK6 as a Ca2+-dependent protease inhibitable by alpha1-PDX yet distinct from furin in inhibitor and substrate profile, clarifying functional redundancy among convertases.","evidence":"In vitro/in vivo acyl-intermediate complex formation, Ca2+/inhibitor enzyme assays, furin-null cell complementation, and antisense knockdown in HepG2","pmids":["10467177","10215603","10050053"],"confidence":"High","gaps":["Degree of in vivo redundancy with furin/PC7 tissue-specific","Non-redundant substrates not yet defined"]},{"year":2000,"claim":"Knockout and epistasis analysis placed PCSK6 genetically upstream of Nodal in axis formation, assigning it a developmental morphogen-processing role.","evidence":"Spc4-null mice, gene expression analysis, and chimeric embryo experiments showing situs ambiguus and craniofacial defects","pmids":["10809672"],"confidence":"High","gaps":["Direct Nodal cleavage by PCSK6 not demonstrated in this study","Cell-of-origin for the activity unresolved"]},{"year":2002,"claim":"Linking PCSK6 overexpression to MMP processing and invasion implicated it in tumor progression through proteolytic activation of MMP zymogens.","evidence":"PACE4 transfection of keratinocytes/SCC cells with prostromelysin-3, MT2-MMP, MMP-2/-9 processing and invasion assays, plus antibody inhibition","pmids":["9393739","11960907","11917148"],"confidence":"Medium","gaps":["Direct vs indirect MMP activation not fully separated","P4-arginine specificity rules tested only in vitro"]},{"year":2005,"claim":"Identifying the cysteine-rich domain as a TIMP-2-dependent cell-surface anchor explained how PCSK6 is positioned for pericellular substrate processing, and transgenic models confirmed MT-MMP activation drives invasion in vivo.","evidence":"CRD deletion, Co-IP/colocalization with TIMP-2, heparin displacement, TIMP-2-null reconstitution; keratinocyte-targeted transgenic mice with MT1/MT2-MMP processing and carcinogenesis","pmids":["16135528","16103082"],"confidence":"High","gaps":["Quantitative contribution of TIMP-2 vs heparan-sulfate anchoring in vivo unresolved"]},{"year":2006,"claim":"RCN-3 was shown to chaperone the PCSK6 precursor and enhance its autoactivation/secretion, adding an ER cofactor to the maturation pathway.","evidence":"Substrate trapping, pulse-chase, Co-IP, and Ca2+-ionophore experiments in GH4C1 cells","pmids":["16433634"],"confidence":"Medium","gaps":["RCN-3 requirement in vivo not tested","Single-lab Co-IP without reciprocal genetic validation"]},{"year":2008,"claim":"The Cripto-PACE4/furin complex and cell-surface Nodal processing mechanism explained how PCSK6 spatially restricts Nodal maturation, and paracrine assays extended this to pluripotency and endoderm induction.","evidence":"Co-IP, brefeldin A/density fractionation, antibody-uptake imaging; transgenic reporter live-imaging and conditional knockouts in embryos","pmids":["18772886","21896659"],"confidence":"High","gaps":["Stoichiometry and structure of the Cripto-convertase-Nodal complex unknown"]},{"year":2008,"claim":"Defining preprohepcidin processing at the RRRRR59 site added an iron-homeostasis substrate to the PCSK6 repertoire, again within a redundant convertase group.","evidence":"Cell transfection in Huh-7/LoVo, cleavage-site mutagenesis, and in vitro peptide digestion","pmids":["18664504"],"confidence":"High","gaps":["Relative in vivo contribution of PCSK6 vs furin/PC5/PC7 not established"]},{"year":2015,"claim":"Demonstrating that PCSK6 activates corin at R801, with Pcsk6-null mice showing salt-sensitive hypertension and human CORIN variants resistant to PCSK6, established a definitive physiological substrate and disease axis.","evidence":"siRNA, overexpression, purified-protein cleavage with R801A mutant, Pcsk6 knockout mice, and human variant testing","pmids":["26259032","29180304"],"confidence":"High","gaps":["Whether corin activation occurs at the membrane or in soluble form physiologically partially open","Tissue-specific contribution to blood pressure regulation"]},{"year":2014,"claim":"Showing isoform-selective maturation of insulin receptor B revealed PCSK6 substrate discrimination distinct from furin and tied it to mitogenic signaling.","evidence":"Furin-deficient cell transfection with IRB/IRA processing analysis and pharmacological PACE4 inhibition","pmids":["25527501"],"confidence":"Medium","gaps":["Physiological relevance of IRB-selective processing in vivo untested"]},{"year":2017,"claim":"Discovery of the methylation-sensitive PACE4-altCT splice isoform that is intracellularly retained, hyper-autoactivates, and processes pro-GDF15 provided a mechanism for PCSK6-driven prostate cancer.","evidence":"Splicing/methylation analysis, subcellular localization, and pro-GDF15 processing across cancer cell lines","pmids":["28993410","23126600"],"confidence":"Medium","gaps":["In vivo tumor dependence on altCT isoform not demonstrated","Full altCT substrate set unknown"]},{"year":2020,"claim":"Vascular and cardiac studies established PCSK6 as a regulator of SMC contractility/migration via MMP14 activation and as a hypoxic cardiomyocyte-secreted driver of fibroblast TGF-β/SMAD3 signaling and cardiac fibrosis.","evidence":"In situ PLA for MMP2/MMP14 interaction, Pcsk6-/- carotid ligation and remodeling models, secretome analysis, and AAV9 cardiomyocyte overexpression","pmids":["31893970","32100557","32325687"],"confidence":"High","gaps":["Direct protease substrate underlying TGF-β activation in fibrosis not pinpointed","Whether MMP14 activation is direct cleavage vs indirect"]},{"year":2024,"claim":"Identifying MT5-MMP as a PCSK6 substrate (cleaved at RRRNKR) linked PCSK6 to amyloidogenic APP processing and cognitive deficits in Alzheimer's disease models.","evidence":"Cleavage-motif mutagenesis, Co-IP, N2A cleavage assays, and AAV PCSK6 knockdown in APP23/PS45 mice with LTP and spatial memory readouts","pmids":["38216110"],"confidence":"High","gaps":["Human AD relevance not established","Contribution relative to other MT5-MMP activators unknown"]},{"year":2023,"claim":"Non-canonical roles emerged: PCSK6 binds and promotes STAT1 phosphorylation to drive Th1 differentiation and colitis, and is an antigenic target in NSAID-associated membranous nephropathy.","evidence":"Co-IP with STAT1, Pcsk6-KO DSS colitis model, T-cell differentiation assays; laser-microdissection MS/MS and immunofluorescence of glomeruli","pmids":["37211384","37119877"],"confidence":"Medium","gaps":["Whether STAT1 regulation requires protease activity untested","Mechanistic role of PCSK6 protease activity in nephropathy not tested","Single-lab findings"]},{"year":null,"claim":"How PCSK6 substrate selectivity is structurally encoded and which substrates it processes non-redundantly in each tissue remain unresolved.","evidence":"","pmids":[],"confidence":"Medium","gaps":["No structural model of substrate recognition in the corpus","Tissue-specific non-redundant substrate set undefined","Mechanism distinguishing protease-dependent vs protease-independent (e.g. STAT1) functions unknown"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0140096","term_label":"catalytic activity, acting on a protein","supporting_discovery_ids":[0,1,8,24,31]},{"term_id":"GO:0016787","term_label":"hydrolase activity","supporting_discovery_ids":[0,8,24]},{"term_id":"GO:0008092","term_label":"cytoskeletal protein binding","supporting_discovery_ids":[13]}],"localization":[{"term_id":"GO:0005783","term_label":"endoplasmic reticulum","supporting_discovery_ids":[4,7,15]},{"term_id":"GO:0005886","term_label":"plasma membrane","supporting_discovery_ids":[5,13,18]},{"term_id":"GO:0005576","term_label":"extracellular region","supporting_discovery_ids":[4,21,30]}],"pathway":[{"term_id":"R-HSA-392499","term_label":"Metabolism of proteins","supporting_discovery_ids":[0,4,19,24]},{"term_id":"R-HSA-1266738","term_label":"Developmental Biology","supporting_discovery_ids":[11,18,21]},{"term_id":"R-HSA-1474244","term_label":"Extracellular matrix organization","supporting_discovery_ids":[6,14,29]},{"term_id":"R-HSA-1643685","term_label":"Disease","supporting_discovery_ids":[24,27,30,31]},{"term_id":"R-HSA-162582","term_label":"Signal Transduction","supporting_discovery_ids":[18,30,36]}],"complexes":[],"partners":["TIMP2","CRIPTO","RCN3","MMP14","MMP2","STAT1"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"P29122","full_name":"Proprotein convertase subtilisin/kexin type 6","aliases":["Paired basic amino acid cleaving enzyme 4","Subtilisin-like proprotein convertase 4","SPC4","Subtilisin/kexin-like protease PACE4"],"length_aa":969,"mass_kda":106.4,"function":"Serine endoprotease that processes various proproteins by cleavage at paired basic amino acids, recognizing the RXXX[KR]R consensus motif. Likely functions in the constitutive secretory pathway, with unique restricted distribution in both neuroendocrine and non-neuroendocrine tissues","subcellular_location":"Secreted","url":"https://www.uniprot.org/uniprotkb/P29122/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/PCSK6","classification":"Not Classified","n_dependent_lines":0,"n_total_lines":74,"dependency_fraction":0.0},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/PCSK6","total_profiled":1310},"omim":[{"mim_id":"619032","title":"RETICULOCALBIN 3; RCN3","url":"https://www.omim.org/entry/619032"},{"mim_id":"603349","title":"ENDOTHELIAL PAS DOMAIN PROTEIN 1; EPAS1","url":"https://www.omim.org/entry/603349"},{"mim_id":"167405","title":"PROPROTEIN CONVERTASE SUBTILISIN/KEXIN TYPE 6; PCSK6","url":"https://www.omim.org/entry/167405"},{"mim_id":"136950","title":"FURIN, PAIRED BASIC AMINO ACID CLEAVING ENZYME; FURIN","url":"https://www.omim.org/entry/136950"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"","locations":[],"tissue_specificity":"Tissue enhanced","tissue_distribution":"Detected in many","driving_tissues":[{"tissue":"brain","ntpm":108.7},{"tissue":"liver","ntpm":149.2},{"tissue":"lymphoid tissue","ntpm":76.5}],"url":"https://www.proteinatlas.org/search/PCSK6"},"hgnc":{"alias_symbol":["SPC4"],"prev_symbol":["PACE4"]},"alphafold":{"accession":"P29122","domains":[{"cath_id":"3.30.70.850","chopping":"70-144","consensus_level":"high","plddt":87.8683,"start":70,"end":144},{"cath_id":"3.40.50.200","chopping":"166-493","consensus_level":"high","plddt":92.5253,"start":166,"end":493},{"cath_id":"2.60.120.260","chopping":"500-633","consensus_level":"high","plddt":96.0696,"start":500,"end":633},{"cath_id":"-","chopping":"801-831","consensus_level":"medium","plddt":80.811,"start":801,"end":831},{"cath_id":"-","chopping":"943-969","consensus_level":"medium","plddt":62.0852,"start":943,"end":969}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/P29122","model_url":"https://alphafold.ebi.ac.uk/files/AF-P29122-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-P29122-F1-predicted_aligned_error_v6.png","plddt_mean":81.38},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=PCSK6","jax_strain_url":"https://www.jax.org/strain/search?query=PCSK6"},"sequence":{"accession":"P29122","fasta_url":"https://rest.uniprot.org/uniprotkb/P29122.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/P29122/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/P29122"}},"corpus_meta":[{"pmid":"8468318","id":"PMC_8468318","title":"Identification and functional expression of a new member of the mammalian Kex2-like processing endoprotease family: its striking structural similarity to PACE4.","date":"1993","source":"Journal of biochemistry","url":"https://pubmed.ncbi.nlm.nih.gov/8468318","citation_count":201,"is_preprint":false},{"pmid":"10809672","id":"PMC_10809672","title":"SPC4/PACE4 regulates a TGFbeta signaling network during axis formation.","date":"2000","source":"Genes & development","url":"https://pubmed.ncbi.nlm.nih.gov/10809672","citation_count":136,"is_preprint":false},{"pmid":"26259032","id":"PMC_26259032","title":"PCSK6-mediated corin activation is essential for normal blood pressure.","date":"2015","source":"Nature medicine","url":"https://pubmed.ncbi.nlm.nih.gov/26259032","citation_count":109,"is_preprint":false},{"pmid":"9166946","id":"PMC_9166946","title":"Comparative analysis of expression of the proprotein convertases furin, PACE4, PC1 and PC2 in human lung tumours.","date":"1997","source":"British journal of cancer","url":"https://pubmed.ncbi.nlm.nih.gov/9166946","citation_count":108,"is_preprint":false},{"pmid":"21051773","id":"PMC_21051773","title":"PCSK6 is associated with handedness in individuals with dyslexia.","date":"2010","source":"Human molecular genetics","url":"https://pubmed.ncbi.nlm.nih.gov/21051773","citation_count":94,"is_preprint":false},{"pmid":"8698813","id":"PMC_8698813","title":"SPC4, SPC6, and the novel protease SPC7 are coexpressed with bone morphogenetic proteins at distinct sites during embryogenesis.","date":"1996","source":"The Journal of cell biology","url":"https://pubmed.ncbi.nlm.nih.gov/8698813","citation_count":85,"is_preprint":false},{"pmid":"23908247","id":"PMC_23908247","title":"Profiling of atherosclerotic lesions by gene and tissue microarrays reveals PCSK6 as a novel protease in unstable carotid atherosclerosis.","date":"2013","source":"Arteriosclerosis, thrombosis, and vascular biology","url":"https://pubmed.ncbi.nlm.nih.gov/23908247","citation_count":78,"is_preprint":false},{"pmid":"7891135","id":"PMC_7891135","title":"Distinct mRNA expression of the highly homologous convertases PC5 and PACE4 in the rat brain and pituitary.","date":"1995","source":"The Journal of neuroscience : the official journal of the Society for Neuroscience","url":"https://pubmed.ncbi.nlm.nih.gov/7891135","citation_count":78,"is_preprint":false},{"pmid":"16135528","id":"PMC_16135528","title":"The cysteine-rich domain of the secreted proprotein convertases PC5A and PACE4 functions as a cell surface anchor and interacts with tissue inhibitors of metalloproteinases.","date":"2005","source":"Molecular biology of the cell","url":"https://pubmed.ncbi.nlm.nih.gov/16135528","citation_count":75,"is_preprint":false},{"pmid":"10900462","id":"PMC_10900462","title":"The proprotein convertases furin and PACE4 play a significant role in tumor progression.","date":"2000","source":"Molecular carcinogenesis","url":"https://pubmed.ncbi.nlm.nih.gov/10900462","citation_count":69,"is_preprint":false},{"pmid":"18772886","id":"PMC_18772886","title":"Cripto recruits Furin and PACE4 and controls Nodal trafficking during proteolytic maturation.","date":"2008","source":"The EMBO journal","url":"https://pubmed.ncbi.nlm.nih.gov/18772886","citation_count":69,"is_preprint":false},{"pmid":"7720860","id":"PMC_7720860","title":"Comparative proteolytic processing of rat prosomatostatin by the convertases PC1, PC2, furin, PACE4 and PC5 in constitutive and regulated secretory pathways.","date":"1995","source":"FEBS letters","url":"https://pubmed.ncbi.nlm.nih.gov/7720860","citation_count":65,"is_preprint":false},{"pmid":"32100557","id":"PMC_32100557","title":"Secretome Analysis of Cardiomyocytes Identifies PCSK6 (Proprotein Convertase Subtilisin/Kexin Type 6) as a Novel Player in Cardiac Remodeling After Myocardial Infarction.","date":"2020","source":"Circulation","url":"https://pubmed.ncbi.nlm.nih.gov/32100557","citation_count":64,"is_preprint":false},{"pmid":"8218226","id":"PMC_8218226","title":"PACE4 is a member of the mammalian propeptidase family that has overlapping but not identical substrate specificity to PACE.","date":"1993","source":"Biochemistry","url":"https://pubmed.ncbi.nlm.nih.gov/8218226","citation_count":59,"is_preprint":false},{"pmid":"21633671","id":"PMC_21633671","title":"Molecular Validation of PACE4 as a Target in Prostate Cancer.","date":"2011","source":"Translational oncology","url":"https://pubmed.ncbi.nlm.nih.gov/21633671","citation_count":59,"is_preprint":false},{"pmid":"9032441","id":"PMC_9032441","title":"PACE4: a subtilisin-like endoprotease with unique properties.","date":"1997","source":"The Biochemical journal","url":"https://pubmed.ncbi.nlm.nih.gov/9032441","citation_count":57,"is_preprint":false},{"pmid":"17909005","id":"PMC_17909005","title":"Opposing function of the proprotein convertases furin and PACE4 on breast cancer cells' malignant phenotypes: role of tissue inhibitors of metalloproteinase-1.","date":"2007","source":"Cancer research","url":"https://pubmed.ncbi.nlm.nih.gov/17909005","citation_count":55,"is_preprint":false},{"pmid":"9393739","id":"PMC_9393739","title":"Expression of PACE4 in chemically induced carcinomas is associated with spindle cell tumor conversion and increased invasive ability.","date":"1997","source":"Cancer research","url":"https://pubmed.ncbi.nlm.nih.gov/9393739","citation_count":46,"is_preprint":false},{"pmid":"31893970","id":"PMC_31893970","title":"PCSK6 Is a Key Protease in the Control of Smooth Muscle Cell Function in Vascular Remodeling.","date":"2020","source":"Circulation research","url":"https://pubmed.ncbi.nlm.nih.gov/31893970","citation_count":45,"is_preprint":false},{"pmid":"10467177","id":"PMC_10467177","title":"Inactivation of proprotein convertase, PACE4, by alpha1-antitrypsin Portland (alpha1-PDX), a blocker of proteolytic activation of bone morphogenetic protein during embryogenesis: evidence that PACE4 is able to form an SDS-stable acyl intermediate with alpha1-PDX.","date":"1999","source":"Journal of biochemistry","url":"https://pubmed.ncbi.nlm.nih.gov/10467177","citation_count":44,"is_preprint":false},{"pmid":"8070361","id":"PMC_8070361","title":"PACE4: a subtilisin-like endoprotease prevalent in the anterior pituitary and regulated by thyroid status.","date":"1994","source":"Endocrinology","url":"https://pubmed.ncbi.nlm.nih.gov/8070361","citation_count":44,"is_preprint":false},{"pmid":"16103082","id":"PMC_16103082","title":"PACE4 expression in mouse basal keratinocytes results in basement membrane disruption and acceleration of tumor progression.","date":"2005","source":"Cancer research","url":"https://pubmed.ncbi.nlm.nih.gov/16103082","citation_count":44,"is_preprint":false},{"pmid":"11960907","id":"PMC_11960907","title":"Malignant conversion of non-tumorigenic murine skin keratinocytes overexpressing PACE4.","date":"2002","source":"Carcinogenesis","url":"https://pubmed.ncbi.nlm.nih.gov/11960907","citation_count":44,"is_preprint":false},{"pmid":"22440827","id":"PMC_22440827","title":"A role for PACE4 in osteoarthritis pain: evidence from human genetic association and null mutant phenotype.","date":"2012","source":"Annals of the rheumatic diseases","url":"https://pubmed.ncbi.nlm.nih.gov/22440827","citation_count":43,"is_preprint":false},{"pmid":"23126600","id":"PMC_23126600","title":"The Multi-Leu peptide inhibitor discriminates between PACE4 and furin and exhibits antiproliferative effects on prostate cancer cells.","date":"2012","source":"Journal of medicinal chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/23126600","citation_count":43,"is_preprint":false},{"pmid":"9234799","id":"PMC_9234799","title":"A role for PACE4 in the proteolytic activation of anthrax toxin protective antigen.","date":"1997","source":"Infection and immunity","url":"https://pubmed.ncbi.nlm.nih.gov/9234799","citation_count":42,"is_preprint":false},{"pmid":"16433634","id":"PMC_16433634","title":"A proteomic approach reveals transient association of reticulocalbin-3, a novel member of the CREC family, with the precursor of subtilisin-like proprotein convertase, PACE4.","date":"2006","source":"The Biochemical journal","url":"https://pubmed.ncbi.nlm.nih.gov/16433634","citation_count":42,"is_preprint":false},{"pmid":"21722156","id":"PMC_21722156","title":"Identification and functional validation of CDH11, PCSK6 and SH3GL3 as novel glioma invasion-associated candidate genes.","date":"2012","source":"Neuropathology and applied neurobiology","url":"https://pubmed.ncbi.nlm.nih.gov/21722156","citation_count":40,"is_preprint":false},{"pmid":"8262218","id":"PMC_8262218","title":"Proprotein processing activity and cleavage site selectivity of the Kex2-like endoprotease PACE4.","date":"1993","source":"FEBS letters","url":"https://pubmed.ncbi.nlm.nih.gov/8262218","citation_count":40,"is_preprint":false},{"pmid":"31726573","id":"PMC_31726573","title":"Aerobic degradation of 3,3',4,4'-tetrachlorobiphenyl by a resuscitated strain Castellaniella sp. SPC4: Kinetics model and pathway for biodegradation.","date":"2019","source":"The Science of the total environment","url":"https://pubmed.ncbi.nlm.nih.gov/31726573","citation_count":38,"is_preprint":false},{"pmid":"9013936","id":"PMC_9013936","title":"The developmental expression in the rat CNS and peripheral tissues of proteases PC5 and PACE4 mRNAs: comparison with other proprotein processing enzymes.","date":"1997","source":"Developmental biology","url":"https://pubmed.ncbi.nlm.nih.gov/9013936","citation_count":38,"is_preprint":false},{"pmid":"8995442","id":"PMC_8995442","title":"Endoprotease activities other than furin and PACE4 with a role in processing of HIV-I gp160 glycoproteins in CHO-K1 cells.","date":"1997","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/8995442","citation_count":38,"is_preprint":false},{"pmid":"37119877","id":"PMC_37119877","title":"Proprotein convertase subtilisin/kexin type 6 (PCSK6) is a likely antigenic target in membranous nephropathy and nonsteroidal anti-inflammatory drug use.","date":"2023","source":"Kidney international","url":"https://pubmed.ncbi.nlm.nih.gov/37119877","citation_count":36,"is_preprint":false},{"pmid":"28993410","id":"PMC_28993410","title":"PACE4 Undergoes an Oncogenic Alternative Splicing Switch in Cancer.","date":"2017","source":"Cancer research","url":"https://pubmed.ncbi.nlm.nih.gov/28993410","citation_count":36,"is_preprint":false},{"pmid":"21896659","id":"PMC_21896659","title":"The microenvironment patterns the pluripotent mouse epiblast through paracrine Furin and Pace4 proteolytic activities.","date":"2011","source":"Genes & development","url":"https://pubmed.ncbi.nlm.nih.gov/21896659","citation_count":36,"is_preprint":false},{"pmid":"8179631","id":"PMC_8179631","title":"Identification of novel cDNAs encoding human kexin-like protease, PACE4 isoforms.","date":"1994","source":"Biochemical and biophysical research communications","url":"https://pubmed.ncbi.nlm.nih.gov/8179631","citation_count":36,"is_preprint":false},{"pmid":"36780644","id":"PMC_36780644","title":"PCSK6 and Survival in Idiopathic Pulmonary Fibrosis.","date":"2023","source":"American journal of respiratory and critical care medicine","url":"https://pubmed.ncbi.nlm.nih.gov/36780644","citation_count":35,"is_preprint":false},{"pmid":"9378725","id":"PMC_9378725","title":"Genomic organization and alternative splicing of human PACE4 (SPC4), kexin-like processing endoprotease.","date":"1997","source":"Journal of biochemistry","url":"https://pubmed.ncbi.nlm.nih.gov/9378725","citation_count":32,"is_preprint":false},{"pmid":"25682874","id":"PMC_25682874","title":"PACE4 inhibitors and their peptidomimetic analogs block prostate cancer tumor progression through quiescence induction, increased apoptosis and impaired neovascularisation.","date":"2015","source":"Oncotarget","url":"https://pubmed.ncbi.nlm.nih.gov/25682874","citation_count":32,"is_preprint":false},{"pmid":"35576690","id":"PMC_35576690","title":"AKAP12 ameliorates liver injury via targeting PI3K/AKT/PCSK6 pathway.","date":"2022","source":"Redox biology","url":"https://pubmed.ncbi.nlm.nih.gov/35576690","citation_count":31,"is_preprint":false},{"pmid":"9738469","id":"PMC_9738469","title":"Biosynthetic processing and quaternary interactions of proprotein convertase SPC4 (PACE4).","date":"1998","source":"FEBS letters","url":"https://pubmed.ncbi.nlm.nih.gov/9738469","citation_count":29,"is_preprint":false},{"pmid":"10050053","id":"PMC_10050053","title":"Subtilisin-like proprotein convertases, PACE4 and PC8, as well as furin, are endogenous proalbumin convertases in HepG2 cells.","date":"1999","source":"Journal of biochemistry","url":"https://pubmed.ncbi.nlm.nih.gov/10050053","citation_count":29,"is_preprint":false},{"pmid":"26744331","id":"PMC_26744331","title":"Gene network and familial analyses uncover a gene network involving Tbx5/Osr1/Pcsk6 interaction in the second heart field for atrial septation.","date":"2016","source":"Human molecular genetics","url":"https://pubmed.ncbi.nlm.nih.gov/26744331","citation_count":28,"is_preprint":false},{"pmid":"18664504","id":"PMC_18664504","title":"Regulation of prohepcidin processing and activity by the subtilisin-like proprotein convertases Furin, PC5, PACE4 and PC7.","date":"2008","source":"Gut","url":"https://pubmed.ncbi.nlm.nih.gov/18664504","citation_count":27,"is_preprint":false},{"pmid":"24818756","id":"PMC_24818756","title":"Implications of Proprotein Convertases in Ovarian Cancer Cell Proliferation and Tumor Progression: Insights for PACE4 as a Therapeutic Target.","date":"2014","source":"Translational oncology","url":"https://pubmed.ncbi.nlm.nih.gov/24818756","citation_count":27,"is_preprint":false},{"pmid":"24913567","id":"PMC_24913567","title":"miR-124 exhibits antiproliferative and antiaggressive effects on prostate cancer cells through PACE4 pathway.","date":"2014","source":"The Prostate","url":"https://pubmed.ncbi.nlm.nih.gov/24913567","citation_count":26,"is_preprint":false},{"pmid":"9192737","id":"PMC_9192737","title":"A novel human PACE4 isoform, PACE4E is an active processing protease containing a hydrophobic cluster at the carboxy terminus.","date":"1997","source":"Journal of biochemistry","url":"https://pubmed.ncbi.nlm.nih.gov/9192737","citation_count":26,"is_preprint":false},{"pmid":"8906861","id":"PMC_8906861","title":"Functional analysis of human PACE4-A and PACE4-C isoforms: identification of a new PACE4-CS isoform.","date":"1996","source":"FEBS letters","url":"https://pubmed.ncbi.nlm.nih.gov/8906861","citation_count":25,"is_preprint":false},{"pmid":"11917148","id":"PMC_11917148","title":"Development of selectivity of alpha1-antitrypsin variant by mutagenesis in its reactive site loop against proprotein convertase. A crucial role of the P4 arginine in PACE4 inhibition.","date":"2002","source":"Protein engineering","url":"https://pubmed.ncbi.nlm.nih.gov/11917148","citation_count":24,"is_preprint":false},{"pmid":"10215603","id":"PMC_10215603","title":"Endoprotease PACE4 is Ca2+-dependent and temperature-sensitive and can partly rescue the phenotype of a furin-deficient cell strain.","date":"1999","source":"The Biochemical journal","url":"https://pubmed.ncbi.nlm.nih.gov/10215603","citation_count":21,"is_preprint":false},{"pmid":"25527501","id":"PMC_25527501","title":"The paired basic amino acid-cleaving enzyme 4 (PACE4) is involved in the maturation of insulin receptor isoform B: an opportunity to reduce the specific insulin receptor-dependent effects of insulin-like growth factor 2 (IGF2).","date":"2014","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/25527501","citation_count":21,"is_preprint":false},{"pmid":"25433529","id":"PMC_25433529","title":"Inhibition of PCSK6 may play a protective role in the development of rheumatoid arthritis.","date":"2014","source":"The Journal of rheumatology","url":"https://pubmed.ncbi.nlm.nih.gov/25433529","citation_count":20,"is_preprint":false},{"pmid":"33359561","id":"PMC_33359561","title":"Up-regulation of PCSK6 by lipid oxidation products: A possible role in atherosclerosis.","date":"2021","source":"Biochimie","url":"https://pubmed.ncbi.nlm.nih.gov/33359561","citation_count":20,"is_preprint":false},{"pmid":"34301174","id":"PMC_34301174","title":"Up-regulation of microRNA-135 or silencing of PCSK6 attenuates inflammatory response in preeclampsia by restricting NLRP3 inflammasome.","date":"2021","source":"Molecular medicine (Cambridge, Mass.)","url":"https://pubmed.ncbi.nlm.nih.gov/34301174","citation_count":20,"is_preprint":false},{"pmid":"26416966","id":"PMC_26416966","title":"PC7 and the related proteases Furin and Pace4 regulate E-cadherin function during blastocyst formation.","date":"2015","source":"The Journal of cell biology","url":"https://pubmed.ncbi.nlm.nih.gov/26416966","citation_count":19,"is_preprint":false},{"pmid":"19520771","id":"PMC_19520771","title":"Subtilisin-like proprotein convertase PACE4 is required for skeletal muscle differentiation.","date":"2009","source":"Journal of biochemistry","url":"https://pubmed.ncbi.nlm.nih.gov/19520771","citation_count":19,"is_preprint":false},{"pmid":"10833428","id":"PMC_10833428","title":"Highly regulated expression of subtilisin-like proprotein convertase PACE4 (SPC4) during dentinogenesis.","date":"2000","source":"Biochemical and biophysical research communications","url":"https://pubmed.ncbi.nlm.nih.gov/10833428","citation_count":18,"is_preprint":false},{"pmid":"26921480","id":"PMC_26921480","title":"The PCSK6 gene is associated with handedness, the autism spectrum, and magical ideation in a non-clinical population.","date":"2016","source":"Neuropsychologia","url":"https://pubmed.ncbi.nlm.nih.gov/26921480","citation_count":17,"is_preprint":false},{"pmid":"8060295","id":"PMC_8060295","title":"The tissue distribution of mRNAs for the PACE4 isoforms, kexin-like processing protease: PACE4C and PACE4D mRNAs are major transcripts among PACE4 isoforms.","date":"1994","source":"Biochemical and biophysical research communications","url":"https://pubmed.ncbi.nlm.nih.gov/8060295","citation_count":17,"is_preprint":false},{"pmid":"37061139","id":"PMC_37061139","title":"PCSK6 attenuates cardiac dysfunction in doxorubicin-induced cardiotoxicity by regulating autophagy.","date":"2023","source":"Free radical biology & medicine","url":"https://pubmed.ncbi.nlm.nih.gov/37061139","citation_count":16,"is_preprint":false},{"pmid":"25333574","id":"PMC_25333574","title":"PACE4 regulates proliferation, migration and invasion in human breast cancer MDA-MB-231 cells.","date":"2014","source":"Molecular medicine reports","url":"https://pubmed.ncbi.nlm.nih.gov/25333574","citation_count":16,"is_preprint":false},{"pmid":"17914070","id":"PMC_17914070","title":"Regulation of Pcsk6 expression during the preantral to antral follicle transition in mice: opposing roles of FSH and oocytes.","date":"2007","source":"Biology of reproduction","url":"https://pubmed.ncbi.nlm.nih.gov/17914070","citation_count":16,"is_preprint":false},{"pmid":"7931173","id":"PMC_7931173","title":"Correlation of proteolytic cleavage of F protein precursors in paramyxoviruses with expression of the fur, PACE4 and PC6 genes in mammalian cells.","date":"1994","source":"The Journal of general virology","url":"https://pubmed.ncbi.nlm.nih.gov/7931173","citation_count":16,"is_preprint":false},{"pmid":"17825503","id":"PMC_17825503","title":"Transcriptional regulation of subtilisin-like proprotein convertase PACE4 by E2F: possible role of E2F-mediated upregulation of PACE4 in tumor progression.","date":"2007","source":"Gene","url":"https://pubmed.ncbi.nlm.nih.gov/17825503","citation_count":16,"is_preprint":false},{"pmid":"24557631","id":"PMC_24557631","title":"Estrogen stimuli promote osteoblastic differentiation via the subtilisin-like proprotein convertase PACE4 in MC3T3-E1 cells.","date":"2014","source":"Journal of bone and mineral metabolism","url":"https://pubmed.ncbi.nlm.nih.gov/24557631","citation_count":16,"is_preprint":false},{"pmid":"29180304","id":"PMC_29180304","title":"Functional analysis of corin protein domains required for PCSK6-mediated activation.","date":"2017","source":"The international journal of biochemistry & cell biology","url":"https://pubmed.ncbi.nlm.nih.gov/29180304","citation_count":15,"is_preprint":false},{"pmid":"10633867","id":"PMC_10633867","title":"Subtilisin-like proprotein convertase PACE4 (SPC4) is a candidate processing enzyme of bone morphogenetic proteins during tooth formation.","date":"1999","source":"Developmental dynamics : an official publication of the American Association of Anatomists","url":"https://pubmed.ncbi.nlm.nih.gov/10633867","citation_count":15,"is_preprint":false},{"pmid":"24860148","id":"PMC_24860148","title":"PCSK6 regulated by LH inhibits the apoptosis of human granulosa cells via activin A and TGFβ2.","date":"2014","source":"The Journal of endocrinology","url":"https://pubmed.ncbi.nlm.nih.gov/24860148","citation_count":15,"is_preprint":false},{"pmid":"28347547","id":"PMC_28347547","title":"PACE4 is an important driver of ZR-75-1 estrogen receptor-positive breast cancer proliferation and tumor progression.","date":"2017","source":"European journal of cell biology","url":"https://pubmed.ncbi.nlm.nih.gov/28347547","citation_count":15,"is_preprint":false},{"pmid":"11736660","id":"PMC_11736660","title":"Proprotein convertase PACE4 is down-regulated by the basic helix-loop-helix transcription factor hASH-1 and MASH-1.","date":"2001","source":"The Biochemical journal","url":"https://pubmed.ncbi.nlm.nih.gov/11736660","citation_count":15,"is_preprint":false},{"pmid":"35456517","id":"PMC_35456517","title":"Pcsk6 Deficiency Promotes Cardiomyocyte Senescence by Modulating Ddit3-Mediated ER Stress.","date":"2022","source":"Genes","url":"https://pubmed.ncbi.nlm.nih.gov/35456517","citation_count":14,"is_preprint":false},{"pmid":"25220591","id":"PMC_25220591","title":"PACE4-based molecular targeting of prostate cancer using an engineered ⁶⁴Cu-radiolabeled peptide inhibitor.","date":"2014","source":"Neoplasia (New York, N.Y.)","url":"https://pubmed.ncbi.nlm.nih.gov/25220591","citation_count":13,"is_preprint":false},{"pmid":"26751825","id":"PMC_26751825","title":"Novel Insights into Structure-Activity Relationships of N-Terminally Modified PACE4 Inhibitors.","date":"2016","source":"ChemMedChem","url":"https://pubmed.ncbi.nlm.nih.gov/26751825","citation_count":13,"is_preprint":false},{"pmid":"26604689","id":"PMC_26604689","title":"PACE4 regulates apoptosis in human prostate cancer cells via endoplasmic reticulum stress and mitochondrial signaling pathways.","date":"2015","source":"Drug design, development and therapy","url":"https://pubmed.ncbi.nlm.nih.gov/26604689","citation_count":11,"is_preprint":false},{"pmid":"14561729","id":"PMC_14561729","title":"The expression of proprotein convertase PACE4 is highly regulated by Hash-2 in placenta: possible role of placenta-specific basic helix-loop-helix transcription factor, human achaete-scute homologue-2.","date":"2003","source":"Journal of biochemistry","url":"https://pubmed.ncbi.nlm.nih.gov/14561729","citation_count":10,"is_preprint":false},{"pmid":"17351018","id":"PMC_17351018","title":"Engineering of alpha1-antitrypsin variants selective for subtilisin-like proprotein convertases PACE4 and PC6: importance of the P2' residue in stable complex formation of the serpin with proprotein convertase.","date":"2007","source":"Protein engineering, design & selection : PEDS","url":"https://pubmed.ncbi.nlm.nih.gov/17351018","citation_count":10,"is_preprint":false},{"pmid":"28287731","id":"PMC_28287731","title":"Positional Scanning Identifies the Molecular Determinants of a High Affinity Multi-Leucine Inhibitor for Furin and PACE4.","date":"2017","source":"Journal of medicinal chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/28287731","citation_count":10,"is_preprint":false},{"pmid":"31825978","id":"PMC_31825978","title":"Serum PCSK6 and corin levels are not associated with cardiovascular outcomes in patients undergoing coronary angiography.","date":"2019","source":"PloS one","url":"https://pubmed.ncbi.nlm.nih.gov/31825978","citation_count":9,"is_preprint":false},{"pmid":"36612240","id":"PMC_36612240","title":"Identification of Genes Associated with Liver Metastasis in Pancreatic Cancer Reveals PCSK6 as a Crucial Mediator.","date":"2022","source":"Cancers","url":"https://pubmed.ncbi.nlm.nih.gov/36612240","citation_count":9,"is_preprint":false},{"pmid":"19013448","id":"PMC_19013448","title":"Inhibition and transcriptional silencing of a subtilisin-like proprotein convertase, PACE4/SPC4, reduces the branching morphogenesis of and AQP5 expression in rat embryonic submandibular gland.","date":"2008","source":"Developmental biology","url":"https://pubmed.ncbi.nlm.nih.gov/19013448","citation_count":9,"is_preprint":false},{"pmid":"32449780","id":"PMC_32449780","title":"Paired Basic Amino Acid-cleaving Enzyme 4 (PCSK6): An Emerging New Target Molecule in Human Melanoma.","date":"2020","source":"Acta dermato-venereologica","url":"https://pubmed.ncbi.nlm.nih.gov/32449780","citation_count":8,"is_preprint":false},{"pmid":"37149637","id":"PMC_37149637","title":"Circ_0002984 promotes proliferation, migration and inflammatory cytokine secretion and inhibits apoptosis of rheumatoid arthritis fibroblast-like synoviocytes by inducing PCSK6 through miR-543.","date":"2023","source":"Journal of orthopaedic surgery and research","url":"https://pubmed.ncbi.nlm.nih.gov/37149637","citation_count":8,"is_preprint":false},{"pmid":"30765725","id":"PMC_30765725","title":"Enhanced anti-tumor activity of the Multi-Leu peptide PACE4 inhibitor transformed into an albumin-bound tumor-targeting prodrug.","date":"2019","source":"Scientific reports","url":"https://pubmed.ncbi.nlm.nih.gov/30765725","citation_count":8,"is_preprint":false},{"pmid":"37211384","id":"PMC_37211384","title":"PCSK6 mediates Th1 differentiation and promotes chronic colitis progression and mucosal barrier injury via STAT1.","date":"2023","source":"Aging","url":"https://pubmed.ncbi.nlm.nih.gov/37211384","citation_count":7,"is_preprint":false},{"pmid":"32325687","id":"PMC_32325687","title":"Lack of PCSK6 Increases Flow-Mediated Outward Arterial Remodeling in Mice.","date":"2020","source":"Cells","url":"https://pubmed.ncbi.nlm.nih.gov/32325687","citation_count":7,"is_preprint":false},{"pmid":"24845697","id":"PMC_24845697","title":"Enhanced aggressiveness of benzopyrene-induced squamous carcinomas in transgenic mice overexpressing the proprotein convertase PACE4 (PCSK6).","date":"2014","source":"Molecular carcinogenesis","url":"https://pubmed.ncbi.nlm.nih.gov/24845697","citation_count":7,"is_preprint":false},{"pmid":"28483279","id":"PMC_28483279","title":"Macrocyclization of a potent PACE4 inhibitor: Benefits and limitations.","date":"2017","source":"European journal of cell biology","url":"https://pubmed.ncbi.nlm.nih.gov/28483279","citation_count":7,"is_preprint":false},{"pmid":"30340539","id":"PMC_30340539","title":"Evaluation of PACE4 isoforms as biomarkers in thyroid cancer.","date":"2018","source":"Journal of otolaryngology - head & neck surgery = Le Journal d'oto-rhino-laryngologie et de chirurgie cervico-faciale","url":"https://pubmed.ncbi.nlm.nih.gov/30340539","citation_count":6,"is_preprint":false},{"pmid":"31115778","id":"PMC_31115778","title":"Structural Asymmetry in the Frontal and Temporal Lobes Is Associated with PCSK6 VNTR Polymorphism.","date":"2019","source":"Molecular neurobiology","url":"https://pubmed.ncbi.nlm.nih.gov/31115778","citation_count":6,"is_preprint":false},{"pmid":"35410344","id":"PMC_35410344","title":"PACE4-altCT isoform of proprotein convertase PACE4 as tissue and plasmatic biomarker for prostate cancer.","date":"2022","source":"Scientific reports","url":"https://pubmed.ncbi.nlm.nih.gov/35410344","citation_count":5,"is_preprint":false},{"pmid":"37937296","id":"PMC_37937296","title":"Bone Mesenchymal Stem Cell-Derived Small Extracellular Vesicles Ameliorated Lipopolysaccharide-Induced Lung Injury Via the miR-21-5p/PCSK6 Pathway.","date":"2023","source":"Journal of immunology research","url":"https://pubmed.ncbi.nlm.nih.gov/37937296","citation_count":5,"is_preprint":false},{"pmid":"26114115","id":"PMC_26114115","title":"Multi-Leu PACE4 Inhibitor Retention within Cells Is PACE4 Dependent and a Prerequisite for Antiproliferative Activity.","date":"2015","source":"BioMed research international","url":"https://pubmed.ncbi.nlm.nih.gov/26114115","citation_count":5,"is_preprint":false},{"pmid":"32442927","id":"PMC_32442927","title":"Aberrant corin and PCSK6 in placentas of the maternal hyperinsulinemia IUGR rat model.","date":"2020","source":"Pregnancy hypertension","url":"https://pubmed.ncbi.nlm.nih.gov/32442927","citation_count":5,"is_preprint":false},{"pmid":"26908617","id":"PMC_26908617","title":"The handedness-associated PCSK6 locus spans an intronic promoter regulating novel transcripts.","date":"2016","source":"Human molecular genetics","url":"https://pubmed.ncbi.nlm.nih.gov/26908617","citation_count":5,"is_preprint":false},{"pmid":"38216110","id":"PMC_38216110","title":"PCSK6 exacerbates Alzheimer's disease pathogenesis by promoting MT5-MMP maturation.","date":"2024","source":"Experimental neurology","url":"https://pubmed.ncbi.nlm.nih.gov/38216110","citation_count":4,"is_preprint":false},{"pmid":"17083113","id":"PMC_17083113","title":"Temporospatially regulated expression of subtilisin-like proprotein convertase PACE4 (SPC4) during development of the rat submandibular gland.","date":"2007","source":"Developmental dynamics : an official publication of the American Association of Anatomists","url":"https://pubmed.ncbi.nlm.nih.gov/17083113","citation_count":3,"is_preprint":false},{"pmid":"32119574","id":"PMC_32119574","title":"Upregulation of PACE4 in prostate cancer is not dependent on E2F transcription factors.","date":"2020","source":"Canadian journal of physiology and pharmacology","url":"https://pubmed.ncbi.nlm.nih.gov/32119574","citation_count":3,"is_preprint":false},{"pmid":"30501188","id":"PMC_30501188","title":"Improving the Selectivity of PACE4 Inhibitors through Modifications of the P1 Residue.","date":"2018","source":"Journal of medicinal chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/30501188","citation_count":3,"is_preprint":false},{"pmid":"27779720","id":"PMC_27779720","title":"PACE4 regulates apoptosis in human pancreatic cancer Panc‑1 cells via the mitochondrial signaling pathway.","date":"2016","source":"Molecular medicine reports","url":"https://pubmed.ncbi.nlm.nih.gov/27779720","citation_count":3,"is_preprint":false},{"pmid":"37555521","id":"PMC_37555521","title":"Enhancing the Drug-Like Profile of a Potent Peptide PACE4 Inhibitor by the Formation of a Host-Guest Inclusion Complex with β-Cyclodextrin.","date":"2023","source":"Molecular pharmaceutics","url":"https://pubmed.ncbi.nlm.nih.gov/37555521","citation_count":3,"is_preprint":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":50514,"output_tokens":9033,"usd":0.143518,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":19048,"output_tokens":5420,"usd":0.11537,"stage2_stop_reason":"end_turn"},"total_usd":0.258888,"stage1_batch_id":"msgbatch_013a8chtv3AWyTqv4z4sEF4C","stage2_batch_id":"msgbatch_01AHsuW63vinsvuTgzmQ3n62","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 1993,\n      \"finding\": \"PC6 (PCSK6) is a subtilisin-like serine endoprotease capable of cleaving precursor proteins at dibasic sites, with a catalytic domain closely related to furin, PC2, PC1/3, PC4, and PACE4, and contains a COOH-terminal Cys-rich region similar to PACE4.\",\n      \"method\": \"Transfection experiments with cleavage assays; cDNA cloning and sequence analysis\",\n      \"journal\": \"Journal of biochemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Weak — transfection-based cleavage assay in single lab, single method\",\n      \"pmids\": [\"8468318\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1993,\n      \"finding\": \"PACE4 (PCSK6) processes pro-von Willebrand factor to its mature form at paired basic residues, with substrate specificity overlapping but not identical to furin; efficient cleavage requires both P4 arginine and P2 lysine, and PACE4 is not inhibited by alpha1-antitrypsin Pittsburgh mutant (unlike furin).\",\n      \"method\": \"Transient DNA cotransfection assay with pro-vWF substrate; inhibitor studies with alpha1-antitrypsin Pittsburgh mutant\",\n      \"journal\": \"Biochemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — two orthogonal methods (cotransfection processing assay + inhibitor specificity), single lab\",\n      \"pmids\": [\"8218226\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1993,\n      \"finding\": \"PACE4 processes pro-von Willebrand factor with cleavage site selectivity similar to PC6A but different from furin.\",\n      \"method\": \"Recombinant vaccinia virus-based expression with vWF cleavage site mutants\",\n      \"journal\": \"FEBS letters\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — independent replication of pro-vWF processing by PACE4, with mutant substrate panel\",\n      \"pmids\": [\"8262218\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1995,\n      \"finding\": \"PACE4 processes prosomatostatin to generate somatostatin-28 (S-28) and somatostatin-14 (S-14) in constitutive secreting LoVo cells, making it a candidate S-28 and S-14 convertase.\",\n      \"method\": \"Recombinant vaccinia virus coexpression of PACE4 with rat prosomatostatin; HPLC analysis of processed products\",\n      \"journal\": \"FEBS letters\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — direct in vitro processing assay with product identification, single lab\",\n      \"pmids\": [\"7720860\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1997,\n      \"finding\": \"PACE4 biosynthesis involves intracellular cleavage of the propeptide (proPACE4 ~106 kDa to PACE4 ~97 kDa) before secretion; PACE4 is not stored in regulated secretory granules; PACE4 enzyme activity is distinctly sensitive to leupeptin inhibition and relatively insensitive to Ca2+ chelators and dithiothreitol, and is not inhibited by the alpha1-antitrypsin Portland variant that potently inhibits furin.\",\n      \"method\": \"Transfected neuroendocrine and fibroblast cell lines; pulse-chase biosynthesis; enzyme activity assays with various inhibitors\",\n      \"journal\": \"The Biochemical journal\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — multiple orthogonal methods (biosynthesis, subcellular fractionation, enzyme inhibition), single lab\",\n      \"pmids\": [\"9032441\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1997,\n      \"finding\": \"PACE4 can activate anthrax toxin protective antigen (PA) at the cell surface, recognizing the sequences RKKR and RAAR (and to a lesser extent KR); PACE4 is present at the exterior of cells and can activate substrates extracellularly.\",\n      \"method\": \"Furin-deficient CHO cells (FD11) transfected with PACE4; in vitro cleavage assays with iodinated PA and mutant substrates; cytotoxicity assays\",\n      \"journal\": \"Infection and immunity\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — cell-based and in vitro cleavage assays with substrate mutants, single lab\",\n      \"pmids\": [\"9234799\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1997,\n      \"finding\": \"PACE4 overexpression in squamous cell carcinoma cells results in enhanced invasiveness and processing of prostromelysin-3 (MMP-11) into its active form, implicating PACE4 in tumor progression via MMP activation.\",\n      \"method\": \"PACE4 cDNA transfection in mouse SCC cells; invasion assays; prostromelysin-3 processing assays\",\n      \"journal\": \"Cancer research\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — gain-of-function transfection with defined substrate (prostromelysin-3) processing and functional invasion readout, single lab\",\n      \"pmids\": [\"9393739\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1998,\n      \"finding\": \"SPC4/PACE4 propeptide cleavage occurs mainly through a unimolecular autocatalytic process in the endoplasmic reticulum (ER); propeptide cleavage is a prerequisite for ER export; the precursor exists as both monomer and dimer, while mature SPC4 is only monomeric.\",\n      \"method\": \"Site-directed mutagenesis of autocatalytic site; sedimentation velocity analysis; chemical cross-linking; transfected fibroblast cells\",\n      \"journal\": \"FEBS letters\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — site-directed mutagenesis establishing autocatalysis + sedimentation/cross-linking for oligomeric state, multiple orthogonal methods\",\n      \"pmids\": [\"9738469\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1999,\n      \"finding\": \"PACE4 forms an SDS-stable acyl-intermediate complex (~180 kDa) with alpha1-antitrypsin Portland (alpha1-PDX) both in vivo and in vitro, demonstrating that alpha1-PDX inhibits PACE4. PACE4 is a Ca2+-dependent protease with optimal Ca2+ requirement of 2 mM, highest activity at weakly basic pH, and activity completely inhibited by EDTA and EGTA but not by leupeptin.\",\n      \"method\": \"In vivo and in vitro complex formation assays; immunological characterization of secreted PACE4; enzyme activity measurements with Ca2+ chelators and inhibitors\",\n      \"journal\": \"Journal of biochemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — direct in vitro and in vivo biochemical characterization with covalent complex demonstration and enzymatic characterization, multiple methods\",\n      \"pmids\": [\"10467177\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1999,\n      \"finding\": \"PACE4 rescues processing of LDL receptor-related protein and pro-insulin receptor and pro-von Willebrand factor in furin-null RPE.40 cells; PACE4 activity in vitro is Ca2+-dependent and temperature-sensitive (22–37°C) unlike furin; PACE4 does not process Pseudomonas exotoxin A.\",\n      \"method\": \"Furin-deficient CHO cell complementation; in vitro endoprotease assays; Northern analysis\",\n      \"journal\": \"The Biochemical journal\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — furin-null cell complementation with multiple substrates and in vitro enzyme characterization, single lab\",\n      \"pmids\": [\"10215603\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1999,\n      \"finding\": \"PACE4, furin, and PC8 are functionally redundant endogenous proalbumin convertases in HepG2 hepatoma cells, each contributing approximately 30% of proalbumin processing activity.\",\n      \"method\": \"Antisense RNA stable expression in HepG2 cells; coexpression studies; Northern blot; ribonuclease protection assay\",\n      \"journal\": \"Journal of biochemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — antisense knockdown with quantified processing readout, coexpression validation, single lab\",\n      \"pmids\": [\"10050053\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2000,\n      \"finding\": \"SPC4 (PCSK6) is genetically upstream of nodal, pitx2, lefty1, and lefty2 in L/R axis formation; SPC4 acts primarily in the foregut during A/P axis formation as shown by chimeric embryo analysis; SPC4-null embryos develop situs ambiguus and craniofacial defects.\",\n      \"method\": \"Genetic knockout mouse; gene expression analysis; chimeric embryo analysis; genetic interaction studies with nodal\",\n      \"journal\": \"Genes & development\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — knockout mouse phenotype combined with epistasis analysis and chimeric embryo experiments, replicated findings across multiple approaches\",\n      \"pmids\": [\"10809672\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2002,\n      \"finding\": \"PACE4 overexpression converts non-tumorigenic keratinocytes to invasive malignant cells; processing of stromelysin-3 (MMP-11), MT2-MMP, MMP-2, and MMP-9 is enhanced by PACE4; inhibition of PACE4 with a specific antibody reduced invasion and MMP processing.\",\n      \"method\": \"Full-length PACE4 cDNA transfection of non-tumorigenic keratinocyte cell lines; in vitro and in vivo invasion assays; antibody inhibition; MMP processing assays\",\n      \"journal\": \"Carcinogenesis\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — gain-of-function and antibody inhibition with defined substrate processing and functional readout, single lab\",\n      \"pmids\": [\"11960907\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2005,\n      \"finding\": \"The cysteine-rich domain (CRD) of PACE4 (and PC5A) functions as a cell surface anchor and interacts with TIMP-2; CRD is essential for cell surface tethering and colocalizes/coimmunoprecipitates with full-length and C-terminal domain of TIMP-2; surface-bound PC5A/PACE4 can be displaced by heparin, suramin, heparinases, or excess TIMP-2.\",\n      \"method\": \"Confocal microscopy; coimmunoprecipitation; biochemical fractionation; heparin displacement; TIMP-2 null fibroblasts with reconstitution; CRD deletion analysis\",\n      \"journal\": \"Molecular biology of the cell\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — multiple orthogonal methods (Co-IP, confocal colocalization, domain deletion, null cell reconstitution, displacement experiments) establishing CRD function\",\n      \"pmids\": [\"16135528\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2005,\n      \"finding\": \"PACE4 overexpression in transgenic mouse basal keratinocytes results in increased processing of MT1-MMP and MT2-MMP, leading to collagenase IV (MMP-2) activation, collagen type IV degradation, basement membrane disruption, and accelerated tumor invasion after chemical carcinogenesis.\",\n      \"method\": \"Transgenic mice with keratinocyte-targeted PACE4 expression; MT-MMP processing assays; collagenase activity assays; histological analysis; chemical carcinogenesis protocol\",\n      \"journal\": \"Cancer research\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — in vivo transgenic model with defined substrate processing (MT1-MMP, MT2-MMP) and functional readout, multiple orthogonal experiments\",\n      \"pmids\": [\"16103082\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2006,\n      \"finding\": \"Reticulocalbin-3 (RCN-3), a Ca2+-binding protein of the CREC family, transiently associates with the precursor form of PACE4 (proPACE4) but not with mature PACE4; this association occurs in the ER and involves the RXNR target sequences in RCN-3; RCN-3 coexpression increases autoactivation and secretion of PACE4.\",\n      \"method\": \"Alpha1-antitrypsin inhibitor-based substrate trapping in GH4C1 cells; protein sequence analysis; biosynthetic pulse-chase studies; co-immunoprecipitation; Ca2+ ionophore experiments\",\n      \"journal\": \"The Biochemical journal\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — Co-IP, substrate trapping, and functional secretion assays, single lab\",\n      \"pmids\": [\"16433634\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2007,\n      \"finding\": \"PACE4 inhibition in MDA-MB-231 breast cancer cells (via ppPACE4 prosegment or alpha1-PDX) increases MMP-9 activity, reduces TIMP-1 secretion, and enhances cell motility, migration, and collagen invasion; in contrast, furin inhibition decreased MMP-9 activity and reduced these functions, demonstrating opposing roles.\",\n      \"method\": \"Stable overexpression of PC inhibitors (alpha1-PDX and ppPACE4) in breast cancer cells; MMP activity assays; TIMP-1 ELISA; migration and invasion assays\",\n      \"journal\": \"Cancer research\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — stable expression with multiple functional readouts and defined substrate pathway, single lab\",\n      \"pmids\": [\"17909005\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2007,\n      \"finding\": \"E2F1, E2F2, and E2F3 transcription factors upregulate PACE4 expression by binding to two E2F consensus sites (-117/-110 and -86/-79) in the 5'-flanking region of the PACE4 gene; mutation of these sites abolished PACE4 promoter response to E2F1.\",\n      \"method\": \"Promoter luciferase assays; EMSA (electrophoretic mobility-shift assay); site-directed mutagenesis; mRNA expression analysis in tumor vs. normal cells\",\n      \"journal\": \"Gene\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — mutagenesis of transcription factor binding sites confirmed by EMSA and promoter assays, single lab\",\n      \"pmids\": [\"17825503\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2008,\n      \"finding\": \"Cripto binds the proprotein convertases Furin and PACE4 and localizes Nodal processing at the cell surface; Cripto and uncleaved Nodal associate during secretion; a Cripto-interacting region in the Nodal propeptide potentiates the effect of proteolytic maturation on Nodal signaling; Nodal is exported to the cell surface before entering the TGN/endosomal system.\",\n      \"method\": \"Co-immunoprecipitation; brefeldin A treatment; density fractionation; antibody uptake experiments; GFP-Flotillin colocalization; coexpression studies\",\n      \"journal\": \"The EMBO journal\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — multiple orthogonal methods (Co-IP, subcellular fractionation, live-cell imaging, pharmacological disruption) establishing the Cripto-PACE4 complex and cell surface processing mechanism\",\n      \"pmids\": [\"18772886\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2008,\n      \"finding\": \"PACE4, along with furin, PC5, and PC7, processes preprohepcidin at the RRRRR59DT site to generate mature hepcidin peptides; this processing was confirmed by site-directed mutagenesis of the cleavage site and in vitro digestion of a synthetic peptide mimicking the cleavage site.\",\n      \"method\": \"Cell transfection in Huh-7 and LoVo (PC-deficient) cells; site-directed mutagenesis; in vitro peptide digestion assays; furin inhibitor studies\",\n      \"journal\": \"Gut\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — site-directed mutagenesis confirming cleavage site + in vitro peptide cleavage assay + PC-deficient cell complementation, multiple methods single lab\",\n      \"pmids\": [\"18664504\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2009,\n      \"finding\": \"PACE4 is required for skeletal muscle differentiation in C2C12 cells; PACE4 shRNA suppresses myosin light chain (MLC) expression during myogenesis; this effect is rescued by recombinant mature IGF-II; PACE4 expression is induced by a PI3K-dependent positive feedback loop during differentiation.\",\n      \"method\": \"shRNA knockdown of PACE4 in C2C12 cells; MLC expression analysis; IGF-II rescue experiment; PI3K inhibitor (LY294002) treatment\",\n      \"journal\": \"Journal of biochemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — shRNA with rescue experiment and pathway inhibitor confirming mechanism, single lab\",\n      \"pmids\": [\"19520771\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2011,\n      \"finding\": \"Furin and Pace4 are released by the extraembryonic microenvironment, cleave a membrane-bound reporter substrate in adjacent epiblast cells in a paracrine manner, and activate Nodal to maintain pluripotency; secreted Pace4 (but not Furin) stimulates endoderm induction.\",\n      \"method\": \"Transgenic reporter substrate live imaging; conditional knockout mouse embryos; paracrine activity assays in embryo culture\",\n      \"journal\": \"Genes & development\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — live-imaging of reporter substrate cleavage in vivo, multiple genetic models, and distinct functional outputs for Pace4 vs Furin\",\n      \"pmids\": [\"21896659\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"PACE4 inhibition by the Multi-Leu peptide (LLLLRVKR) displays ~20-fold selectivity over furin and significantly reduces proliferation of DU145 and LNCaP prostate cancer cell lines, inducing G0/G1 cell cycle arrest; the peptide must enter cells to inhibit proliferation.\",\n      \"method\": \"Enzyme kinetic assays with recombinant PACE4 and furin; cell proliferation assays; cell cycle analysis; cell penetration studies\",\n      \"journal\": \"Journal of medicinal chemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — enzyme kinetics with selectivity quantification and cell-based functional assays, single lab\",\n      \"pmids\": [\"23126600\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"PACE4 selectively supports maturation of insulin receptor isoform B (IRB) at the cell surface when furin-dependent intracellular maturation is inefficient; PACE4 does not preferentially process IRA; selective pharmacological inhibition of PACE4 reduces IRA maturation and mitogenic signaling.\",\n      \"method\": \"Furin-deficient cell transfection; IRB/IRA isoform processing analysis; cell surface receptor assays; PACE4 inhibitor treatment\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — isoform-selective processing demonstrated in furin-deficient cells with pharmacological validation, single lab\",\n      \"pmids\": [\"25527501\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"PCSK6 cleaves and activates corin at the R801 site; PCSK6 siRNA knockdown inhibits corin activation; PCSK6 overexpression enhances corin activation; purified PCSK6 cleaves wild-type corin but not R801A mutant; Pcsk6-knockout mice develop salt-sensitive hypertension with undetectable corin activation and pro-ANP processing activity; CORIN variants associated with hypertension are defective in PCSK6-mediated activation.\",\n      \"method\": \"siRNA knockdown; overexpression in cultured cells; purified protein cleavage assay with site mutant (R801A); Pcsk6 knockout mice with physiological phenotyping; pro-ANP processing assay\",\n      \"journal\": \"Nature medicine\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — in vitro reconstitution with site-mutant corin + in vivo Pcsk6 KO phenotype + human variant validation, multiple orthogonal methods across multiple experimental systems\",\n      \"pmids\": [\"26259032\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"PC7, Furin, and Pace4 jointly regulate E-cadherin processing during morula compaction and blastocyst inner cell mass formation; differential inhibition reveals all three PCs are active in overlapping but partially non-overlapping compartments (inner and outer cells).\",\n      \"method\": \"PC mutant mouse embryos; live imaging of transgenic reporter substrate; pharmacological inhibition with common inhibitor; E-cadherin processing analysis\",\n      \"journal\": \"The Journal of cell biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — live-imaging reporter combined with genetic and pharmacological approaches, single lab\",\n      \"pmids\": [\"26416966\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"Tbx5 directly regulates Pcsk6 transcription in the posterior second heart field; this was validated by ChIP-qPCR and luciferase reporter assay; Pcsk6 is part of a Tbx5/Osr1/Pcsk6 gene network for atrial septation.\",\n      \"method\": \"ChIP-qPCR; luciferase reporter assay; RNA-seq; immunohistochemistry; human family genotyping\",\n      \"journal\": \"Human molecular genetics\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — direct transcription factor binding confirmed by ChIP and reporter assay, single lab\",\n      \"pmids\": [\"26744331\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"PACE4 pre-mRNA undergoes DNA methylation-sensitive alternative splicing of its terminal exon, generating an oncogenic C-terminally modified isoform (PACE4-altCT) strongly expressed in prostate cancer; PACE4-altCT displays enhanced autoactivating process, is retained intracellularly (not secreted), and dramatically increases processing of pro-GDF15 as its first identified substrate in prostate cancer.\",\n      \"method\": \"Alternative splicing analysis; DNA methylation studies; subcellular localization; pro-GDF15 processing assays; expression in multiple cancer cell lines\",\n      \"journal\": \"Cancer research\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — multiple mechanistic readouts (splicing, localization, substrate processing) in single lab study\",\n      \"pmids\": [\"28993410\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"Functional analysis reveals that corin lacking the transmembrane domain is activated by PCSK6 in conditioned medium and under cell-free conditions; cell membrane association is not required for PCSK6 to activate corin; soluble corin and PCSK6 are secreted via different intracellular pathways; heparan sulfate/chondroitin sulfate and heparinase/chondroitinase do not alter corin activation by PCSK6; corin pro-peptide domain is dispensable for PCSK6-mediated activation.\",\n      \"method\": \"Corin deletion mutant expression in HEK293 cells; cell-free cleavage assay; monensin blockade; immunostaining; glycosaminoglycan treatment and enzyme treatment\",\n      \"journal\": \"The international journal of biochemistry & cell biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — domain deletion analysis combined with cell-free assay and pharmacological tools, single lab\",\n      \"pmids\": [\"29180304\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"PCSK6 cointeracts with MMP2 and MMP14 in smooth muscle cells (demonstrated by in situ proximity ligation assay); Pcsk6-/- mice show reduced MMP14 activation and decreased intimal hyperplasia after carotid ligation; PCSK6 overexpression increases PDGFBB-induced SMC migration; PCSK6 silencing downregulates contractile SMC markers and increases MMP2 expression.\",\n      \"method\": \"In situ proximity ligation assay for protein interaction; Pcsk6-/- mouse carotid ligation model; aortic ring SMC outgrowth assay; siRNA knockdown in human SMCs; PCSK6 overexpression migration assays; Affymetrix microarrays\",\n      \"journal\": \"Circulation research\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — in situ PLA for protein interaction, in vivo KO phenotype with defined molecular readout (MMP14 activation), and in vitro gain/loss-of-function with multiple orthogonal approaches\",\n      \"pmids\": [\"31893970\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"PCSK6 secreted from hypoxic cardiomyocytes activates TGF-β signaling and SMAD3 translocation in fibroblasts; cardiomyocyte-specific AAV9-mediated PCSK6 overexpression in mice increases collagen I and III expression, cardiac fibrosis, and decreases LV function after MI; PCSK6-depleted cardiomyocyte secretome reduces collagen expression in fibroblasts.\",\n      \"method\": \"Stable isotope labeling secretome analysis; siRNA knockdown; AAV9 cardiomyocyte-specific overexpression in mice; SMAD3 translocation assay; collagen expression analysis; left anterior descending coronary artery ligation model\",\n      \"journal\": \"Circulation\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — in vivo AAV9 overexpression with cardiac phenotype + paracrine functional assays + siRNA mechanistic data, multiple orthogonal methods\",\n      \"pmids\": [\"32100557\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"PCSK6 cleaves and activates MT5-MMP (η-secretase) by recognizing the RRRNKR sequence in its N-terminal propeptide domain; mutation or knockout of this cleavage motif prevents PCSK6 from interacting with and cleaving MT5-MMP; PCSK6 knockdown reduces amyloidogenic APP processing (Aβ production) and ameliorates hippocampal LTP and spatial memory in AD model mice.\",\n      \"method\": \"Site-directed mutagenesis of MT5-MMP cleavage motif; Co-IP; N2A cell cleavage assays; AAV-mediated PCSK6 knockdown in APP23/PS45 transgenic mice; LTP electrophysiology; spatial memory testing\",\n      \"journal\": \"Experimental neurology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — site-directed mutagenesis of cleavage site + Co-IP + in vivo AAV knockdown with cognitive readout, multiple orthogonal methods in single lab\",\n      \"pmids\": [\"38216110\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"PCSK6 is identified as a likely antigenic target in membranous nephropathy associated with NSAID use; IgG from affected patients binds to PCSK6 along the glomerular basement membrane, co-localizing with IgG deposits.\",\n      \"method\": \"Laser microdissection of glomeruli followed by mass spectrometry (MS/MS); protein G immunoprecipitation; immunofluorescence; confocal microscopy; western blot of tissue eluates\",\n      \"journal\": \"Kidney international\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — multiple orthogonal methods (MS/MS, IP, IHC, WB) establishing antigen identity, but mechanistic role of PCSK6 protease activity not directly tested\",\n      \"pmids\": [\"37119877\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2001,\n      \"finding\": \"hASH-1 (and MASH-1) transcription factors downregulate PACE4 gene expression by binding to an E-box cluster (E4-E9) in the 5'-flanking region; this effect is specific to PACE4 and does not affect furin, PC5/6, or PC7/8; other neural bHLH factors tested did not affect PACE4 expression.\",\n      \"method\": \"Luciferase reporter assay; EMSA with hASH-1 binding to E-box cluster; overexpression of hASH-1/MASH-1 in neuroblastoma cell lines; mRNA expression analysis\",\n      \"journal\": \"The Biochemical journal\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — mutagenesis/EMSA confirming E-box binding + reporter assay, multiple methods, single lab\",\n      \"pmids\": [\"11736660\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2002,\n      \"finding\": \"The P4 arginine residue is crucial for PACE4 inhibition by alpha1-antitrypsin variants; an AVRR variant inhibited furin and PC6 but not PACE4; the RVRR variant inhibited both PACE4 and furin but required 600-fold higher concentration to inhibit PC6; these variants form SDS-stable complexes with their respective targets.\",\n      \"method\": \"In vitro enzyme inhibition assays with fluorogenic substrate; SDS-stable complex formation assays ex vivo; inhibition of pro-complement C3 processing\",\n      \"journal\": \"Protein engineering\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — direct in vitro and ex vivo biochemical characterization with defined substrate specificity, multiple inhibitor variants tested, single lab\",\n      \"pmids\": [\"11917148\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"Pcsk6-/- mice display increased flow-mediated outward arterial remodeling; absence of PCSK6 increases lumen circumference and reduces medial contractility (decreased active tension) and SMC contractile markers (SMA, MYH11, LMOD1) in response to increased blood flow.\",\n      \"method\": \"Pcsk6-/- mouse carotid ligation model; ultrasound biomicroscopy; wire myography; immunohistochemistry; transmission electron microscopy\",\n      \"journal\": \"Cells\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — Pcsk6 KO with defined vascular phenotype measured by multiple methods, single lab\",\n      \"pmids\": [\"32325687\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"PCSK6 binds to STAT1 and promotes STAT1 phosphorylation, thereby regulating Th1 cell differentiation; PCSK6 overexpression promotes Th0-to-Th1 conversion, while PCSK6 silencing suppresses it; PCSK6 knockdown in Pcsk6-KO mice ameliorates DSS-induced colitis with decreased Th1 and M1 macrophage proportions.\",\n      \"method\": \"Co-IP (COPI assay) demonstrating PCSK6-STAT1 binding; Pcsk6 KO mouse DSS colitis model; STAT1 inhibitor studies; in vitro T cell differentiation assays\",\n      \"journal\": \"Aging\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — Co-IP confirming interaction + in vivo KO phenotype + in vitro functional assay, single lab\",\n      \"pmids\": [\"37211384\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"PCSK6 (PACE4/SPC4) is a subtilisin-like serine endoprotease that undergoes autocatalytic propeptide removal in the ER as a prerequisite for secretion, then acts at the cell surface and extracellularly to cleave diverse precursor proteins at paired basic residue motifs (R-X-X-R), including corin (activating the ANP/blood pressure pathway), Nodal (controlling left-right and anteroposterior axis formation), MT-MMPs (enabling tumor invasion and vascular remodeling), MT5-MMP (promoting amyloidogenic APP processing in Alzheimer's disease), pro-GDF15, prohepcidin, pro-insulin receptor-B, prostromelysin-3, pro-vWF, and anthrax toxin PA; its C-terminal cysteine-rich domain mediates cell surface tethering via TIMP-2 binding; an oncogenic alternatively spliced isoform (PACE4-altCT) is retained intracellularly and drives prostate cancer progression; and PCSK6 modulates SMC contractility and migration via MMP14 activation in vascular remodeling.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"PCSK6 (PACE4/SPC4) is a calcium-dependent subtilisin-like serine endoprotease that matures secreted and membrane precursor proteins by cleaving at paired basic (R-X-X-R) motifs, with substrate selectivity overlapping but distinct from furin [#0, #1, #8]. Its biosynthesis requires unimolecular autocatalytic removal of the propeptide in the ER as a prerequisite for export, after which mature enzyme is secreted as a monomer and is not stored in regulated secretory granules [#4, #7]; the CREC-family Ca2+-binding protein RCN-3 transiently associates with the proform and promotes its autoactivation and secretion [#15]. A C-terminal cysteine-rich domain tethers PCSK6 to the cell surface via TIMP-2 binding and heparan-sulfate interactions, positioning it to process substrates extracellularly and at the plasma membrane [#5, #13]. Through this activity PCSK6 governs developmental axis formation by acting genetically upstream of Nodal/Pitx2/Lefty in left-right and anteroposterior patterning, processing Nodal at the cell surface in complex with Cripto and acting in paracrine fashion to maintain pluripotency and drive endoderm induction [#11, #18, #21]. It activates corin at R801 to drive pro-ANP processing, and its loss produces salt-sensitive hypertension in mice [#24]. In the vasculature and heart PCSK6 activates MT-MMPs including MMP14 to control smooth muscle contractility, migration and arterial remodeling, and acts as a hypoxic cardiomyocyte-secreted factor that activates fibroblast TGF-\\u03b2/SMAD3 signaling to promote cardiac fibrosis [#29, #30, #35]. PCSK6 promotes tumor invasion by processing prostromelysin-3 and MT1/MT2-MMP to activate MMP-2 [#6, #14], and a DNA-methylation-sensitive alternatively spliced isoform (PACE4-altCT) is retained intracellularly, hyper-autoactivates, processes pro-GDF15, and drives prostate cancer [#27]. Additional validated substrates include prohepcidin, the insulin receptor B isoform, pro-von Willebrand factor, and the \\u03b7-secretase MT5-MMP, whose activation by PCSK6 promotes amyloidogenic APP processing in Alzheimer's disease models [#19, #23, #1, #31]. PCSK6 expression is transcriptionally controlled by E2F factors and Tbx5 (activating) and hASH-1 (repressing) [#17, #26, #33].\",\n  \"teleology\": [\n    {\n      \"year\": 1993,\n      \"claim\": \"Establishing PCSK6 as a subtilisin-family endoprotease that cleaves precursors at dibasic sites defined its core biochemical identity and substrate logic.\",\n      \"evidence\": \"cDNA cloning, sequence analysis, and cotransfection cleavage assays of pro-vWF with cleavage-site mutants\",\n      \"pmids\": [\"8468318\", \"8218226\", \"8262218\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Physiological substrate repertoire not defined\", \"No structural basis for substrate selectivity vs furin\"]\n    },\n    {\n      \"year\": 1997,\n      \"claim\": \"Defining propeptide cleavage and secretory itinerary showed how PCSK6 is activated and where it acts, distinguishing it from regulated-pathway convertases.\",\n      \"evidence\": \"Pulse-chase biosynthesis, subcellular fractionation, and cell-surface/extracellular cleavage assays in transfected and furin-deficient cells\",\n      \"pmids\": [\"9032441\", \"9234799\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Mechanism of autocatalysis not yet established\", \"Endogenous physiological substrates unproven\"]\n    },\n    {\n      \"year\": 1998,\n      \"claim\": \"Demonstrating unimolecular autocatalytic propeptide removal in the ER as a prerequisite for export resolved the activation mechanism and oligomeric state.\",\n      \"evidence\": \"Site-directed mutagenesis of the autocatalytic site, sedimentation velocity, and chemical cross-linking in transfected fibroblasts\",\n      \"pmids\": [\"9738469\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Chaperones/cofactors of folding and autoactivation not identified at this stage\"]\n    },\n    {\n      \"year\": 1999,\n      \"claim\": \"Biochemical characterization established PCSK6 as a Ca2+-dependent protease inhibitable by alpha1-PDX yet distinct from furin in inhibitor and substrate profile, clarifying functional redundancy among convertases.\",\n      \"evidence\": \"In vitro/in vivo acyl-intermediate complex formation, Ca2+/inhibitor enzyme assays, furin-null cell complementation, and antisense knockdown in HepG2\",\n      \"pmids\": [\"10467177\", \"10215603\", \"10050053\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Degree of in vivo redundancy with furin/PC7 tissue-specific\", \"Non-redundant substrates not yet defined\"]\n    },\n    {\n      \"year\": 2000,\n      \"claim\": \"Knockout and epistasis analysis placed PCSK6 genetically upstream of Nodal in axis formation, assigning it a developmental morphogen-processing role.\",\n      \"evidence\": \"Spc4-null mice, gene expression analysis, and chimeric embryo experiments showing situs ambiguus and craniofacial defects\",\n      \"pmids\": [\"10809672\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Direct Nodal cleavage by PCSK6 not demonstrated in this study\", \"Cell-of-origin for the activity unresolved\"]\n    },\n    {\n      \"year\": 2002,\n      \"claim\": \"Linking PCSK6 overexpression to MMP processing and invasion implicated it in tumor progression through proteolytic activation of MMP zymogens.\",\n      \"evidence\": \"PACE4 transfection of keratinocytes/SCC cells with prostromelysin-3, MT2-MMP, MMP-2/-9 processing and invasion assays, plus antibody inhibition\",\n      \"pmids\": [\"9393739\", \"11960907\", \"11917148\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct vs indirect MMP activation not fully separated\", \"P4-arginine specificity rules tested only in vitro\"]\n    },\n    {\n      \"year\": 2005,\n      \"claim\": \"Identifying the cysteine-rich domain as a TIMP-2-dependent cell-surface anchor explained how PCSK6 is positioned for pericellular substrate processing, and transgenic models confirmed MT-MMP activation drives invasion in vivo.\",\n      \"evidence\": \"CRD deletion, Co-IP/colocalization with TIMP-2, heparin displacement, TIMP-2-null reconstitution; keratinocyte-targeted transgenic mice with MT1/MT2-MMP processing and carcinogenesis\",\n      \"pmids\": [\"16135528\", \"16103082\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Quantitative contribution of TIMP-2 vs heparan-sulfate anchoring in vivo unresolved\"]\n    },\n    {\n      \"year\": 2006,\n      \"claim\": \"RCN-3 was shown to chaperone the PCSK6 precursor and enhance its autoactivation/secretion, adding an ER cofactor to the maturation pathway.\",\n      \"evidence\": \"Substrate trapping, pulse-chase, Co-IP, and Ca2+-ionophore experiments in GH4C1 cells\",\n      \"pmids\": [\"16433634\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"RCN-3 requirement in vivo not tested\", \"Single-lab Co-IP without reciprocal genetic validation\"]\n    },\n    {\n      \"year\": 2008,\n      \"claim\": \"The Cripto-PACE4/furin complex and cell-surface Nodal processing mechanism explained how PCSK6 spatially restricts Nodal maturation, and paracrine assays extended this to pluripotency and endoderm induction.\",\n      \"evidence\": \"Co-IP, brefeldin A/density fractionation, antibody-uptake imaging; transgenic reporter live-imaging and conditional knockouts in embryos\",\n      \"pmids\": [\"18772886\", \"21896659\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Stoichiometry and structure of the Cripto-convertase-Nodal complex unknown\"]\n    },\n    {\n      \"year\": 2008,\n      \"claim\": \"Defining preprohepcidin processing at the RRRRR59 site added an iron-homeostasis substrate to the PCSK6 repertoire, again within a redundant convertase group.\",\n      \"evidence\": \"Cell transfection in Huh-7/LoVo, cleavage-site mutagenesis, and in vitro peptide digestion\",\n      \"pmids\": [\"18664504\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Relative in vivo contribution of PCSK6 vs furin/PC5/PC7 not established\"]\n    },\n    {\n      \"year\": 2015,\n      \"claim\": \"Demonstrating that PCSK6 activates corin at R801, with Pcsk6-null mice showing salt-sensitive hypertension and human CORIN variants resistant to PCSK6, established a definitive physiological substrate and disease axis.\",\n      \"evidence\": \"siRNA, overexpression, purified-protein cleavage with R801A mutant, Pcsk6 knockout mice, and human variant testing\",\n      \"pmids\": [\"26259032\", \"29180304\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Whether corin activation occurs at the membrane or in soluble form physiologically partially open\", \"Tissue-specific contribution to blood pressure regulation\"]\n    },\n    {\n      \"year\": 2014,\n      \"claim\": \"Showing isoform-selective maturation of insulin receptor B revealed PCSK6 substrate discrimination distinct from furin and tied it to mitogenic signaling.\",\n      \"evidence\": \"Furin-deficient cell transfection with IRB/IRA processing analysis and pharmacological PACE4 inhibition\",\n      \"pmids\": [\"25527501\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Physiological relevance of IRB-selective processing in vivo untested\"]\n    },\n    {\n      \"year\": 2017,\n      \"claim\": \"Discovery of the methylation-sensitive PACE4-altCT splice isoform that is intracellularly retained, hyper-autoactivates, and processes pro-GDF15 provided a mechanism for PCSK6-driven prostate cancer.\",\n      \"evidence\": \"Splicing/methylation analysis, subcellular localization, and pro-GDF15 processing across cancer cell lines\",\n      \"pmids\": [\"28993410\", \"23126600\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"In vivo tumor dependence on altCT isoform not demonstrated\", \"Full altCT substrate set unknown\"]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"Vascular and cardiac studies established PCSK6 as a regulator of SMC contractility/migration via MMP14 activation and as a hypoxic cardiomyocyte-secreted driver of fibroblast TGF-\\u03b2/SMAD3 signaling and cardiac fibrosis.\",\n      \"evidence\": \"In situ PLA for MMP2/MMP14 interaction, Pcsk6-/- carotid ligation and remodeling models, secretome analysis, and AAV9 cardiomyocyte overexpression\",\n      \"pmids\": [\"31893970\", \"32100557\", \"32325687\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Direct protease substrate underlying TGF-\\u03b2 activation in fibrosis not pinpointed\", \"Whether MMP14 activation is direct cleavage vs indirect\"]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Identifying MT5-MMP as a PCSK6 substrate (cleaved at RRRNKR) linked PCSK6 to amyloidogenic APP processing and cognitive deficits in Alzheimer's disease models.\",\n      \"evidence\": \"Cleavage-motif mutagenesis, Co-IP, N2A cleavage assays, and AAV PCSK6 knockdown in APP23/PS45 mice with LTP and spatial memory readouts\",\n      \"pmids\": [\"38216110\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Human AD relevance not established\", \"Contribution relative to other MT5-MMP activators unknown\"]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"Non-canonical roles emerged: PCSK6 binds and promotes STAT1 phosphorylation to drive Th1 differentiation and colitis, and is an antigenic target in NSAID-associated membranous nephropathy.\",\n      \"evidence\": \"Co-IP with STAT1, Pcsk6-KO DSS colitis model, T-cell differentiation assays; laser-microdissection MS/MS and immunofluorescence of glomeruli\",\n      \"pmids\": [\"37211384\", \"37119877\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Whether STAT1 regulation requires protease activity untested\", \"Mechanistic role of PCSK6 protease activity in nephropathy not tested\", \"Single-lab findings\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How PCSK6 substrate selectivity is structurally encoded and which substrates it processes non-redundantly in each tissue remain unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No structural model of substrate recognition in the corpus\", \"Tissue-specific non-redundant substrate set undefined\", \"Mechanism distinguishing protease-dependent vs protease-independent (e.g. STAT1) functions unknown\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0140096\", \"supporting_discovery_ids\": [0, 1, 8, 24, 31]},\n      {\"term_id\": \"GO:0016787\", \"supporting_discovery_ids\": [0, 8, 24]},\n      {\"term_id\": \"GO:0008092\", \"supporting_discovery_ids\": [13]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005783\", \"supporting_discovery_ids\": [4, 7, 15]},\n      {\"term_id\": \"GO:0005886\", \"supporting_discovery_ids\": [5, 13, 18]},\n      {\"term_id\": \"GO:0005576\", \"supporting_discovery_ids\": [4, 21, 30]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-392499\", \"supporting_discovery_ids\": [0, 4, 19, 24]},\n      {\"term_id\": \"R-HSA-1266738\", \"supporting_discovery_ids\": [11, 18, 21]},\n      {\"term_id\": \"R-HSA-1474244\", \"supporting_discovery_ids\": [6, 14, 29]},\n      {\"term_id\": \"R-HSA-1643685\", \"supporting_discovery_ids\": [24, 27, 30, 31]},\n      {\"term_id\": \"R-HSA-162582\", \"supporting_discovery_ids\": [18, 30, 36]}\n    ],\n    \"complexes\": [],\n    \"partners\": [\"TIMP2\", \"CRIPTO\", \"RCN3\", \"MMP14\", \"MMP2\", \"STAT1\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":9,"faith_total":9,"faith_pct":100.0}}