{"gene":"MT3","run_date":"2026-04-28T18:30:28","timeline":{"discoveries":[{"year":1991,"finding":"MT3 (GIF) was purified from normal human brain as a 68 amino acid metallothionein-like protein with ~70% identity to MT-II, containing a unique 6 amino acid insert in the C-terminal region; it directly inhibited survival and neurite formation of cortical neurons in vitro, and was markedly reduced in a distinct subset of astrocytes in Alzheimer's disease cortex.","method":"Protein purification, amino acid sequencing, in vitro neuronal survival assay, immunohistochemistry","journal":"Neuron","confidence":"High","confidence_rationale":"Tier 1 — original purification with sequence determination and functional in vitro assay; foundational paper with 622 citations","pmids":["1873033"],"is_preprint":false},{"year":1992,"finding":"MT-III gene was cloned and shown to be brain-restricted in expression and to fail to respond to zinc, cadmium, dexamethasone, or bacterial endotoxin in vivo, distinguishing it from MT-I and MT-II; the gene is closely linked to other MT genes on human chromosome 16.","method":"Molecular cloning, Northern blot, in vivo metal/hormone challenge experiments","journal":"Proceedings of the National Academy of Sciences of the United States of America","confidence":"High","confidence_rationale":"Tier 1-2 — cloning with functional characterization, replicated in multiple species; 544 citations","pmids":["1631128"],"is_preprint":false},{"year":1992,"finding":"Molecular cloning of human GIF cDNA confirmed it as a new metallothionein family member with nervous-system-exclusive expression; recombinant GIF produced in E. coli inhibited the growth of neonatal rat cortical neurons, and GIF mRNA was drastically decreased in AD brains by Northern blot.","method":"cDNA cloning, recombinant protein expression in E. coli, neuronal growth inhibition assay, Northern blot","journal":"The EMBO journal","confidence":"High","confidence_rationale":"Tier 1 — recombinant protein with functional assay, replicated finding; 163 citations","pmids":["1464312"],"is_preprint":false},{"year":1994,"finding":"Recombinant MT-III (but not MT-I) specifically inhibited survival of rat cortical neurons in culture when added to brain extract-supplemented cultures, confirming MT-III as a neuron-specific inhibitory factor; however, MT-III protein and mRNA levels were not significantly decreased in AD frontal cortex relative to controls in this study.","method":"Recombinant protein addition to neuronal cultures, Western blot, immunoassay","journal":"Brain research","confidence":"High","confidence_rationale":"Tier 2 — direct functional assay with recombinant protein and isoform specificity control (MT-I vs MT-III)","pmids":["7953645"],"is_preprint":false},{"year":1996,"finding":"MT-III is expressed predominantly in zinc-containing neurons of the hippocampus (not glia), where it functions as a zinc buffer/regulator, and MT-III knockout mice show heightened sensitivity to kainate-induced seizures, establishing a role for MT-III in neuromodulation and zinc homeostasis in vivo.","method":"Immunohistochemistry, knockout mouse model, kainate seizure assay","journal":"FASEB journal","confidence":"High","confidence_rationale":"Tier 2 — knockout animal phenotype with defined cellular context; 164 citations","pmids":["8751715"],"is_preprint":false},{"year":1998,"finding":"Metal-thiolate cluster formation in the C-terminal alpha-domain of human GIF (residues 32-68) was characterized: with Cu(I), two air-sensitive Cu4S8-9 and Cu6S11 clusters form successively; with Zn(II) or Cd(II), a well-defined M4S11 cluster with tetrahedral coordination forms; 113Cd NMR revealed conformational flexibility of this domain.","method":"Electronic absorption spectroscopy, CD, MCD, luminescence spectroscopy, 113Cd NMR","journal":"Biochemistry","confidence":"High","confidence_rationale":"Tier 1 — multiple orthogonal spectroscopic methods for structural characterization","pmids":["9778374"],"is_preprint":false},{"year":1998,"finding":"MT-3 mRNA expression is not restricted to brain but is also present in rat testis, prostate, epididymis, tongue, ovary, uterus, stomach, heart, and seminal vesicles; prostatic MT-3 mRNA was decreased 75% by orchiectomy and restored by dihydrotestosterone treatment, establishing androgen-dependent regulation of MT-3 in the prostate.","method":"Northern blot, in situ hybridization, orchiectomy/DHT replacement experiments","journal":"DNA and cell biology","confidence":"High","confidence_rationale":"Tier 2 — hormone manipulation experiment with defined molecular readout","pmids":["9655243"],"is_preprint":false},{"year":2000,"finding":"Native GIF contains 4 Cu(I) and 3 Zn(II) ions in homometallic metal-thiolate clusters; stepwise Cu(I) incorporation into recombinant apo-MT-3 reveals cooperative formation of two Cu4S9 clusters (one per domain) and then Cu6S9 and Cu6S11 clusters in beta and alpha domains of fully metallated Cu12-MT-3; the Cu4 cluster preferentially forms in the N-terminal beta-domain.","method":"Electronic absorption, CD, MCD, luminescence spectroscopy, immunochemistry with domain-specific antibodies, limited tryptic digestion","journal":"Journal of inorganic biochemistry","confidence":"High","confidence_rationale":"Tier 1 — multiple complementary spectroscopic and biochemical methods defining cluster localization","pmids":["10830840"],"is_preprint":false},{"year":2001,"finding":"MT-3 (zinc metallothionein) imported into liver mitochondria inhibits respiration; this inhibition is caused specifically by the N-terminal beta-domain via zinc delivery to the electron transfer chain; the alpha-domain alone is inactive in this system, and carbamoylation of lysines attenuates import.","method":"Mitochondrial import assay, respiratory inhibition measurement, isolated domain experiments, chemical modification","journal":"Proceedings of the National Academy of Sciences of the United States of America","confidence":"High","confidence_rationale":"Tier 1 — reconstituted in vitro assay with domain dissection and chemical modification; 204 citations","pmids":["11226237"],"is_preprint":false},{"year":2001,"finding":"The alpha-domain of GIF shows greater capacity to scavenge hydroxyl radicals and eliminate reactive oxygen species than the beta-domain, as demonstrated by EPR spin-trapping; both GIF and its domains protect neurons and PC12 cells from beta-amyloid 25-35 cytotoxicity.","method":"EPR spin-trapping, CytC-VitC radical-producing system, neuronal/PC12 cell cytotoxicity assay","journal":"Biochimica et biophysica acta","confidence":"Medium","confidence_rationale":"Tier 2 — in vitro assay with domain comparison, single lab","pmids":["11750760"],"is_preprint":false},{"year":2002,"finding":"MT-3 binds Zn2+ and Cd2+ noncooperatively (unlike MT-1/MT-2) and can accommodate more than 7 metal ions; the N-terminal beta-cluster accounts for heterogeneity of metalloforms and has higher metal-transfer potential than the beta-cluster of MT-2, suggesting MT-3 functions as a dynamic zinc buffer in zincergic neurons.","method":"Mass spectrometry, pH/stability studies, EDTA competition assay, ultrafiltration","journal":"Biochemistry","confidence":"High","confidence_rationale":"Tier 1 — mass spectrometry with multiple orthogonal analyses, distinct mechanistic property identified","pmids":["11994011"],"is_preprint":false},{"year":2002,"finding":"MT-III protects against DNA strand breaks and deoxyribose degradation induced by Fe3+-NTA/H2O2 and scavenges superoxide anion; alkylation of sulfhydryl groups with N-ethylmaleimide abolishes the protective effect, demonstrating that the cysteine thiolate groups are the active moiety for ROS scavenging.","method":"Plasmid DNA single-strand break assay, deoxyribose degradation assay, xanthine/xanthine oxidase system, NEM chemical modification","journal":"Biochimica et biophysica acta","confidence":"High","confidence_rationale":"Tier 1 — in vitro assay with active-site chemical modification identifying cysteine thiolates as functional groups","pmids":["12383939"],"is_preprint":false},{"year":2002,"finding":"The Cu4-thiolate cluster in MT-3 is located preferentially in the N-terminal beta-domain; using domain-specific antibodies combined with limited tryptic digestion of partially metal-occupied Cu4-MT-3, Cu4S9 cluster was assigned to the beta-domain containing 9 cysteines.","method":"Domain-specific antibody immunochemistry, limited tryptic digestion, CD and luminescence spectroscopy","journal":"Journal of biological inorganic chemistry","confidence":"High","confidence_rationale":"Tier 1-2 — domain localization by antibody/digestion combined with spectroscopy","pmids":["12072966"],"is_preprint":false},{"year":2002,"finding":"Exogenous GIF (MT-III) prevents neurite extension of cortical neurons in early differentiation and protects differentiated neurons from high-oxygen-induced death; ESR spin-trapping showed GIF at 2-6 µM efficiently scavenges hydroxyl radicals (more effectively than MT-I+II at same concentration) but does not scavenge superoxide or NO; antisense knockdown of GIF promoted neuronal death under high oxygen.","method":"Cortical neuron culture, antisense S-oligonucleotide knockdown, ESR spin-trapping with Fenton reaction and H2O2 photolysis","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1-2 — direct functional assay combined with ESR mechanistic analysis and loss-of-function; 101 citations","pmids":["12058024"],"is_preprint":false},{"year":2002,"finding":"Stable transfection of human MT-III into GM00637 fibroblasts conferred significant resistance to H2O2-induced cytotoxicity, reduced ROS production, and protected against DNA damage, directly demonstrating MT-III antioxidant function in non-neural cells.","method":"Stable transfection, H2O2 challenge, LDH cytotoxicity, ROS measurement, comet assay","journal":"FEBS letters","confidence":"Medium","confidence_rationale":"Tier 2 — clean gain-of-function transfection with defined phenotypic readouts, single lab","pmids":["12067712"],"is_preprint":false},{"year":2003,"finding":"CpG island hypermethylation in intron 1 of the MT-3 gene silences its transcription in gastric carcinoma cell lines; treatment with 5-azacytidine (demethylating agent) restored MT-3 mRNA expression, establishing epigenetic regulation of MT-3 as a mechanism for its downregulation in cancer.","method":"Bisulfite sequencing, DHPLC methylation analysis, 5-azacytidine treatment, RT-PCR","journal":"Carcinogenesis","confidence":"High","confidence_rationale":"Tier 2 — pharmacological demethylation restoring expression, confirmed in multiple cell lines and primary tumors","pmids":["12538345"],"is_preprint":false},{"year":2004,"finding":"MT-3 expression in HK-2 (human proximal tubule) cells (stably transfected) sensitized cells to Cd2+-induced cytotoxicity and shifted the mechanism of cell death from apoptosis (no MT-3) to necrosis (with MT-3), demonstrating that MT-3 controls the mode of cell death in response to heavy metal toxicity.","method":"Stable transfection of MT-3 into HK-2 cells, Cd2+ cytotoxicity assay, apoptosis/necrosis characterization","journal":"Toxicological sciences","confidence":"High","confidence_rationale":"Tier 2 — clean gain-of-function experiment with defined mechanistic endpoint (apoptosis vs. necrosis)","pmids":["15129022"],"is_preprint":false},{"year":2006,"finding":"Solution structure of the alpha-domain (residues 32-68) of human MT-3 was determined by multinuclear/multidimensional NMR; the domain forms a metal-thiolate cluster similar in overall fold to mouse MT-3 but with a longer loop in the acidic hexapeptide insertion; backbone dynamics showed the beta-domain has similar internal motion to the alpha-domain though N-terminal residues are more flexible.","method":"Multinuclear multidimensional NMR spectroscopy, molecular dynamics simulated annealing","journal":"FEBS letters","confidence":"High","confidence_rationale":"Tier 1 — NMR structure determination with dynamics analysis","pmids":["16413543"],"is_preprint":false},{"year":2008,"finding":"MT-III protects dopaminergic SH-SY5Y cells against 6-OHDA-induced oxidative stress through a mechanism involving PI3K and ERK kinase activation, Nrf2 nuclear translocation, and upregulation of heme oxygenase-1 (HO-1); inhibiting PI3K or ERK blocked MT-III-induced HO-1 expression and neuroprotection.","method":"Cell viability assay, ROS measurement, kinase inhibitor studies, Nrf2 nuclear fractionation, Western blot for HO-1","journal":"Toxicology and applied pharmacology","confidence":"Medium","confidence_rationale":"Tier 2 — pathway dissection with multiple inhibitors and defined signaling readouts, single lab","pmids":["18554677"],"is_preprint":false},{"year":2008,"finding":"MT-3 mRNA expression in human adipocytes is dramatically (>600-fold) and rapidly (within 60 min) induced by hypoxia (1% O2) and by hypoxia mimetics (CoCl2, desferrioxamine, DMOG), indicating transcriptional regulation through HIF-1; MT-3 was also induced in preadipocytes and detected in human adipose tissue.","method":"PCR arrays, real-time RT-PCR, hypoxia mimetic treatment, preadipocyte cultures","journal":"Biochemical and biophysical research communications","confidence":"Medium","confidence_rationale":"Tier 2 — multiple hypoxia mimetics used, HIF-1 pathway inferred; single lab","pmids":["18206644"],"is_preprint":false},{"year":2010,"finding":"MT-3 regulates lysosomal function: in MT-3-null brain cells, lysosome-associated membrane proteins (LAMP-1/-2) and lysosomal enzyme levels are reduced with decreased autophagic flux; under acute oxidative stress, zinc released from MT-3 accumulates in autolysosomes and triggers lysosomal membrane permeabilization leading to cell death; absence of MT-3 reduces zinc-mediated lysosomal damage and decreases acute cell death.","method":"MT-3 null cell studies, lysosomal enzyme assays, LAMP protein expression, autophagic flux measurement, oxidative stress challenge","journal":"Molecular brain","confidence":"High","confidence_rationale":"Tier 2 — null cell genetic model with defined organelle-level mechanistic readouts; 180 citations","pmids":["20974010"],"is_preprint":false},{"year":2011,"finding":"Zn7-MT-3 removes Cu(II) from the α-synuclein-Cu(II) complex through reduction of Cu(II) by thiolate ligands, forming Cu(I)4Zn4MT-3 with an unusual oxygen-stable Cu(I)4-thiolate cluster; this mechanism abolishes α-Syn catalytic oxidase activity, prevents α-Syn oligomerization, hydroxyl radical production, and dopamine oxidation.","method":"UV-vis and CD spectroscopy, stopped-flow kinetics, mass spectrometry, ROS detection, α-Syn aggregation assay","journal":"Free radical biology & medicine","confidence":"High","confidence_rationale":"Tier 1 — mechanistic in vitro reconstitution with structural characterization of the Cu(I)4-thiolate cluster product","pmids":["21320589"],"is_preprint":false},{"year":2014,"finding":"MT3 promoter hypermethylation silences expression in pediatric AML cell lines and patient samples; lentiviral MT3 overexpression in AML cells inhibited proliferation and induced apoptosis; PCR array analysis identified FOXO1 as dysregulated downstream of MT3 overexpression, suggesting FOXO1 as part of the MT3-mediated pro-apoptotic pathway.","method":"MSP and bisulfite genomic sequencing, lentiviral overexpression, Annexin V apoptosis assay, RT-PCR array","journal":"Journal of translational medicine","confidence":"Medium","confidence_rationale":"Tier 2-3 — gain-of-function with functional readout and downstream pathway gene identified, single lab","pmids":["24962166"],"is_preprint":false},{"year":2016,"finding":"Isothermal titration calorimetry showed Pb2+ binding to Zn7MT-3 displaces each zinc ion with similar ΔG and ΔH; EDTA chelation studies revealed both Zn and Pb are extracted in a tri-phasic process indicating three binding populations with different thermodynamics; metal binding is entropically favored with an enthalpic penalty reflecting cysteine deprotonation upon thiolate ligation.","method":"Isothermal titration calorimetry (ITC), EDTA chelation, CD spectroscopy","journal":"Metallomics","confidence":"High","confidence_rationale":"Tier 1 — rigorous thermodynamic characterization by ITC with multiple metal and structural analyses","pmids":["26757944"],"is_preprint":false},{"year":2017,"finding":"Comprehensive review and experimental synthesis established that MT-3 possesses distinct Cu/Zn metal-thiolate cluster properties compared to MT-1/MT-2; specifically, Zn7MT-3 (but not MT-1/MT-2) protects neuronal cells from toxicity of Cu(II)-bound amyloids (Aβ, α-Syn) by transmetallation, and the unique acidic hexapeptide insert in the C-terminal domain and the N-terminal extension are structural determinants of its distinct biological activity.","method":"Review integrating structural (NMR, spectroscopy) and functional (cell toxicity) data; domain mutagenesis context","journal":"International journal of molecular sciences","confidence":"Medium","confidence_rationale":"Tier 2 — synthesis review citing primary experimental data; 80 citations","pmids":["28538697"],"is_preprint":false},{"year":2019,"finding":"Pb(II) binding to full-length MT3 is relatively unaffected by pH (stable), whereas isolated alpha and beta fragments interact with Pb(II) in a pH-sensitive manner; mass spectrometry revealed Pb-MT3 complexes persist long-term with intact protein but Pb is eventually released from isolated fragments; Zn(II) displacement by Pb(II) is thermodynamically favorable in both intact MT3 and isolated domains.","method":"Spectroscopy, mass spectrometry, isothermal titration calorimetry, pH-dependent binding studies","journal":"Metallomics","confidence":"High","confidence_rationale":"Tier 1 — multiple orthogonal methods (ITC, MS, CD) with domain comparison","pmids":["30516222"],"is_preprint":false},{"year":2020,"finding":"miR-325-3p directly targets the MT3 3'UTR (confirmed by dual-luciferase reporter assay); MT3 overexpression in bladder cancer T24 cells promotes proliferation, invasion, migration, and EMT (increased MMP9, decreased E-cadherin); miR-325-3p mimics suppress these effects by reducing MT3 levels.","method":"Dual-luciferase reporter assay, transwell invasion/migration assay, CCK-8 proliferation assay, Western blot for EMT markers","journal":"Medical science monitor","confidence":"Medium","confidence_rationale":"Tier 2-3 — validated miRNA target with gain/loss-of-function and defined molecular readouts, single lab","pmids":["32512576"],"is_preprint":false}],"current_model":"MT3 (metallothionein-3/GIF) is a brain-enriched, 68-amino acid, cysteine-rich metalloprotein organized into N-terminal beta and C-terminal alpha domains that coordinately sequester Cu(I) (preferentially in the beta-domain as a Cu4-thiolate cluster) and Zn(II) (as an M4S11 cluster in the alpha-domain); it functions as a potent hydroxyl radical scavenger via its cysteine thiolates (more effective than MT-I/II), regulates lysosomal integrity and autophagic flux through zinc dynamics, suppresses the redox activity of Cu(II)-amyloid complexes (including α-synuclein-Cu) by transmetallation, inhibits neuronal survival and neurite outgrowth, modulates apoptosis vs. necrosis cell death fate in cadmium toxicity, and is transcriptionally silenced by CpG island hypermethylation in multiple cancers; MT3 expression is androgen-regulated in the prostate and HIF-1-dependent under hypoxia."},"narrative":{"teleology":[{"year":1991,"claim":"Identification of MT3 as a neuron growth-inhibitory factor resolved the molecular identity of a brain-specific metalloprotein that directly suppresses cortical neuronal survival and neurite outgrowth.","evidence":"Purification from human brain with amino acid sequencing and in vitro cortical neuron assay","pmids":["1873033"],"confidence":"High","gaps":["Mechanism of neurite inhibition unknown","Whether reduced MT3 in AD astrocytes is causative or consequential not resolved"]},{"year":1992,"claim":"Cloning established MT3 as a distinct metallothionein gene with brain-restricted expression and unique transcriptional non-responsiveness to classical MT inducers (zinc, cadmium, dexamethasone), demarcating it from MT-I/II.","evidence":"Molecular cloning, Northern blot, in vivo metal/hormone challenge in multiple species","pmids":["1631128","1464312"],"confidence":"High","gaps":["Transcription factor(s) controlling brain-specific expression not identified","Whether non-responsiveness to metals is promoter-intrinsic not tested"]},{"year":1996,"claim":"MT3 knockout mice revealed an in vivo role in zinc-dependent neuromodulation, showing heightened kainate seizure sensitivity and localizing MT3 to hippocampal zinc-containing neurons rather than glia.","evidence":"MT3 knockout mouse, immunohistochemistry, kainate seizure model","pmids":["8751715"],"confidence":"High","gaps":["Downstream zinc-dependent targets mediating seizure susceptibility unidentified","Contribution of MT3 to synaptic zinc release not directly measured"]},{"year":1998,"claim":"Spectroscopic characterization of recombinant MT3 domains defined the metal-thiolate cluster architecture—Cu4S9 preferentially in the beta-domain, M4S11 in the alpha-domain—establishing the structural basis for MT3's distinct metal-handling properties.","evidence":"Electronic absorption, CD, MCD, luminescence spectroscopy, 113Cd NMR on isolated alpha-domain and full-length protein","pmids":["9778374","10830840","12072966"],"confidence":"High","gaps":["Full-length solution structure not determined at this stage","In vivo metal stoichiometry under physiological conditions uncertain"]},{"year":2001,"claim":"Domain-dissection experiments showed that MT3's beta-domain delivers zinc to mitochondrial respiratory complexes (inhibiting respiration) while its alpha-domain is the primary hydroxyl radical scavenger, establishing domain-specific functional duality.","evidence":"Mitochondrial import/respiration assay with isolated domains; EPR spin-trapping and neuronal/PC12 cytotoxicity assays","pmids":["11226237","11750760"],"confidence":"High","gaps":["Physiological relevance of mitochondrial zinc delivery not confirmed in intact neurons","Relative contributions of the two domains to neuroprotection in vivo unknown"]},{"year":2002,"claim":"Cysteine thiolates were identified as the essential functional groups for MT3's antioxidant activity: NEM alkylation abolished protection against DNA damage and ROS, and ESR spin-trapping demonstrated MT3 scavenges hydroxyl radicals more efficiently than MT-I/II; noncooperative zinc binding and higher metal-transfer potential distinguished MT3 as a dynamic zinc buffer.","evidence":"Plasmid DNA damage assay with NEM modification; ESR spin-trapping; mass spectrometry and EDTA competition for metal binding kinetics","pmids":["12383939","12058024","11994011"],"confidence":"High","gaps":["Structural basis for noncooperative binding not resolved","Whether dynamic zinc buffering occurs on synaptic timescales not tested"]},{"year":2003,"claim":"Epigenetic silencing of MT3 by CpG island hypermethylation was established as a mechanism for its loss in cancer, with 5-azacytidine treatment restoring expression in gastric carcinoma cells.","evidence":"Bisulfite sequencing, DHPLC methylation analysis, 5-azacytidine demethylation in cell lines and primary tumors","pmids":["12538345"],"confidence":"High","gaps":["Whether methylation-mediated silencing is a driver or passenger event in tumorigenesis not determined","Methyl-CpG-binding proteins responsible not identified"]},{"year":2004,"claim":"MT3 was found to modulate cell death fate: its expression in renal cells shifted Cd2+-induced death from apoptosis to necrosis, revealing that MT3 does not simply protect against metal toxicity but actively redirects the mode of cell death.","evidence":"Stable MT3 transfection into HK-2 cells with Cd2+ challenge and apoptosis/necrosis quantification","pmids":["15129022"],"confidence":"High","gaps":["Mechanism by which MT3 switches apoptosis to necrosis (e.g., zinc release, mitochondrial effects) not elucidated","Relevance to neuronal cell death not tested"]},{"year":2010,"claim":"MT3 was shown to regulate lysosomal integrity and autophagic flux through zinc dynamics: MT3-null cells had reduced LAMP-1/2 and lysosomal enzymes, while stress-induced zinc release from MT3 triggered lysosomal membrane permeabilization.","evidence":"MT3-null brain cell studies with lysosomal enzyme assays, LAMP protein quantification, and oxidative stress challenge","pmids":["20974010"],"confidence":"High","gaps":["Identity of the zinc-sensitive lysosomal target(s) unknown","Whether lysosomal zinc release is the mechanism linking MT3 to necrotic death remains correlative"]},{"year":2011,"claim":"Zn7-MT3 was shown to suppress α-synuclein-Cu(II) redox toxicity through transmetallation: MT3's thiolates reduce Cu(II) to Cu(I), sequestering it in an oxygen-stable Cu(I)4-thiolate cluster and abolishing α-Syn oligomerization and ROS production.","evidence":"Stopped-flow kinetics, UV-vis/CD spectroscopy, mass spectrometry, ROS and aggregation assays with reconstituted α-Syn-Cu(II) complexes","pmids":["21320589"],"confidence":"High","gaps":["In vivo relevance to Parkinson's disease pathology not demonstrated","Whether MT3 similarly detoxifies Cu-Aβ complexes in vivo remains unresolved"]},{"year":2016,"claim":"Thermodynamic characterization of Pb(II) binding to MT3 revealed entropically driven displacement of zinc, with three distinct binding populations and pH-stable Pb-MT3 complexes, establishing MT3 as a potential lead sequestrant.","evidence":"Isothermal titration calorimetry, EDTA chelation kinetics, CD spectroscopy on full-length and isolated domains","pmids":["26757944","30516222"],"confidence":"High","gaps":["Physiological relevance of Pb sequestration in neurotoxicity not tested in cellular or animal models","Whether Pb binding disrupts MT3's zinc-buffering or antioxidant functions unknown"]},{"year":null,"claim":"The in vivo mechanisms linking MT3's zinc-release dynamics to lysosomal regulation, the structural determinants of the apoptosis-to-necrosis switch, and the functional significance of MT3 transmetallation in neurodegenerative disease models remain unresolved.","evidence":"","pmids":[],"confidence":"High","gaps":["No conditional knockout studies targeting MT3 in disease models","No high-resolution full-length structure of mixed Cu/Zn-loaded MT3","Direct in vivo evidence for MT3-mediated Cu-amyloid detoxification lacking"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0016209","term_label":"antioxidant activity","supporting_discovery_ids":[9,11,13,14]},{"term_id":"GO:0140313","term_label":"molecular sequestering activity","supporting_discovery_ids":[4,10,21,23,25]},{"term_id":"GO:0008289","term_label":"lipid binding","supporting_discovery_ids":[5,7,10,12]}],"localization":[{"term_id":"GO:0005829","term_label":"cytosol","supporting_discovery_ids":[0,4]},{"term_id":"GO:0005764","term_label":"lysosome","supporting_discovery_ids":[20]},{"term_id":"GO:0005739","term_label":"mitochondrion","supporting_discovery_ids":[8]}],"pathway":[{"term_id":"R-HSA-8953897","term_label":"Cellular responses to stimuli","supporting_discovery_ids":[9,11,13,14,20]},{"term_id":"R-HSA-5357801","term_label":"Programmed Cell Death","supporting_discovery_ids":[16,22]},{"term_id":"R-HSA-9612973","term_label":"Autophagy","supporting_discovery_ids":[20]},{"term_id":"R-HSA-382551","term_label":"Transport of small molecules","supporting_discovery_ids":[5,7,8,10]}],"complexes":[],"partners":["SNCA"],"other_free_text":[]},"mechanistic_narrative":"MT3 (metallothionein-3/GIF) is a brain-enriched, cysteine-rich metalloprotein that coordinates Cu(I) and Zn(II) in distinct metal-thiolate clusters—a Cu4-thiolate cluster preferentially in the N-terminal beta-domain and an M4S11 cluster in the C-terminal alpha-domain—enabling it to function as a dynamic zinc buffer in neurons and to suppress redox-active Cu(II)-amyloid complexes via transmetallation [PMID:10830840, PMID:21320589]. Its cysteine thiolates confer potent hydroxyl radical scavenging activity that exceeds MT-I/II, protecting neurons and non-neural cells from oxidative damage [PMID:12058024, PMID:12383939]. MT3 regulates lysosomal integrity and autophagic flux through zinc dynamics; under oxidative stress, zinc released from MT3 triggers lysosomal membrane permeabilization and cell death, while MT3 absence reduces lysosomal capacity [PMID:20974010]. MT3 is transcriptionally silenced by CpG island hypermethylation in gastric carcinoma and pediatric AML, and its re-expression induces apoptosis and inhibits proliferation in cancer cells [PMID:12538345, PMID:24962166]."},"prefetch_data":{"uniprot":{"accession":"P25713","full_name":"Metallothionein-3","aliases":["GIFB","GIF","Growth inhibitory factor","Metallothionein-III","MT-III"],"length_aa":68,"mass_kda":6.9,"function":"Binds heavy metals. Contains three zinc and three copper atoms per polypeptide chain and only a negligible amount of cadmium. Inhibits survival and neurite formation of cortical neurons in vitro","subcellular_location":"","url":"https://www.uniprot.org/uniprotkb/P25713/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/MT3","classification":"Not Classified","n_dependent_lines":4,"n_total_lines":1208,"dependency_fraction":0.0033112582781456954},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/MT3","total_profiled":1310},"omim":[{"mim_id":"607989","title":"SPARC/OSTEONECTIN, CWCV, AND KAZAL-LIKE DOMAINS PROTEOGLYCAN 3; SPOCK3","url":"https://www.omim.org/entry/607989"},{"mim_id":"606206","title":"METALLOTHIONEIN 4; MT4","url":"https://www.omim.org/entry/606206"},{"mim_id":"602262","title":"MATRIX METALLOPROTEINASE 16; MMP16","url":"https://www.omim.org/entry/602262"},{"mim_id":"139255","title":"METALLOTHIONEIN 3; MT3","url":"https://www.omim.org/entry/139255"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"","locations":[],"tissue_specificity":"Tissue enriched","tissue_distribution":"Detected in many","driving_tissues":[{"tissue":"brain","ntpm":7006.0}],"url":"https://www.proteinatlas.org/search/MT3"},"hgnc":{"alias_symbol":["GIF"],"prev_symbol":[]},"alphafold":{"accession":"P25713","domains":[{"cath_id":"4.10.10.10","chopping":"13-46","consensus_level":"medium","plddt":75.01,"start":13,"end":46}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/P25713","model_url":"https://alphafold.ebi.ac.uk/files/AF-P25713-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-P25713-F1-predicted_aligned_error_v6.png","plddt_mean":69.12},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=MT3","jax_strain_url":"https://www.jax.org/strain/search?query=MT3"},"sequence":{"accession":"P25713","fasta_url":"https://rest.uniprot.org/uniprotkb/P25713.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/P25713/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/P25713"}},"corpus_meta":[{"pmid":"10913150","id":"PMC_10913150","title":"Identification of the melatonin-binding site MT3 as the quinone reductase 2.","date":"2000","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/10913150","citation_count":438,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"33046875","id":"PMC_33046875","title":"A GRF-GIF chimeric protein improves the regeneration efficiency of transgenic plants.","date":"2020","source":"Nature biotechnology","url":"https://pubmed.ncbi.nlm.nih.gov/33046875","citation_count":355,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"24888433","id":"PMC_24888433","title":"Post-transcriptional control of GRF transcription factors by microRNA miR396 and GIF co-activator affects leaf size and longevity.","date":"2014","source":"The Plant journal : for cell and molecular biology","url":"https://pubmed.ncbi.nlm.nih.gov/24888433","citation_count":235,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"7953645","id":"PMC_7953645","title":"Enhanced neurotrophic activity in Alzheimer's disease cortex is not associated with down-regulation of metallothionein-III (GIF).","date":"1994","source":"Brain research","url":"https://pubmed.ncbi.nlm.nih.gov/7953645","citation_count":159,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"19397366","id":"PMC_19397366","title":"An unusually stable G-quadruplex within the 5'-UTR of the MT3 matrix metalloproteinase mRNA represses translation in eukaryotic cells.","date":"2009","source":"Biochemistry","url":"https://pubmed.ncbi.nlm.nih.gov/19397366","citation_count":129,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"14681236","id":"PMC_14681236","title":"Differential inhibition of membrane type 3 (MT3)-matrix metalloproteinase (MMP) and MT1-MMP by tissue inhibitor of metalloproteinase (TIMP)-2 and TIMP-3 rgulates pro-MMP-2 activation.","date":"2003","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/14681236","citation_count":118,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"22266651","id":"PMC_22266651","title":"The porphyrin TmPyP4 unfolds the extremely stable G-quadruplex in MT3-MMP mRNA and alleviates its repressive effect to enhance translation in eukaryotic cells.","date":"2012","source":"Nucleic acids research","url":"https://pubmed.ncbi.nlm.nih.gov/22266651","citation_count":117,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"11290376","id":"PMC_11290376","title":"Involvement of melatonin MT(3) receptors in the regulation of intraocular pressure in rabbits.","date":"2001","source":"European journal of pharmacology","url":"https://pubmed.ncbi.nlm.nih.gov/11290376","citation_count":102,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"9092507","id":"PMC_9092507","title":"Expression of three membrane-type matrix metalloproteinases (MT-MMPs) in rat vascular smooth muscle cells and characterization of MT3-MMPs with and without transmembrane domain.","date":"1997","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/9092507","citation_count":101,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"17910598","id":"PMC_17910598","title":"Melatonin as a naturally occurring co-substrate of quinone reductase-2, the putative MT3 melatonin membrane receptor: hypothesis and significance.","date":"2007","source":"Journal of pineal research","url":"https://pubmed.ncbi.nlm.nih.gov/17910598","citation_count":97,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"24709835","id":"PMC_24709835","title":"An RNA-seq method for defining endoribonuclease cleavage specificity identifies dual rRNA substrates for toxin MazF-mt3.","date":"2014","source":"Nature communications","url":"https://pubmed.ncbi.nlm.nih.gov/24709835","citation_count":87,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"14665622","id":"PMC_14665622","title":"Co-recycling of MT1-MMP and MT3-MMP through the trans-Golgi network. Identification of DKV582 as a recycling signal.","date":"2003","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/14665622","citation_count":87,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"18485066","id":"PMC_18485066","title":"The mRNA interferases, MazF-mt3 and MazF-mt7 from Mycobacterium tuberculosis target unique pentad sequences in single-stranded RNA.","date":"2008","source":"Molecular microbiology","url":"https://pubmed.ncbi.nlm.nih.gov/18485066","citation_count":86,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"12642384","id":"PMC_12642384","title":"Ocular hypotensive effects of melatonin receptor agonists in the rabbit: further evidence for an MT3 receptor.","date":"2003","source":"British journal of pharmacology","url":"https://pubmed.ncbi.nlm.nih.gov/12642384","citation_count":85,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"16293234","id":"PMC_16293234","title":"Characterization of the melatoninergic MT3 binding site on the NRH:quinone oxidoreductase 2 enzyme.","date":"2005","source":"Biochemical pharmacology","url":"https://pubmed.ncbi.nlm.nih.gov/16293234","citation_count":85,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"10355541","id":"PMC_10355541","title":"Expression of MT-3 protein in the human kidney.","date":"1999","source":"Toxicology letters","url":"https://pubmed.ncbi.nlm.nih.gov/10355541","citation_count":83,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"6206179","id":"PMC_6206179","title":"Molecular localization of human class II MT2 and MT3 determinants.","date":"1984","source":"The Journal of experimental medicine","url":"https://pubmed.ncbi.nlm.nih.gov/6206179","citation_count":79,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"30885290","id":"PMC_30885290","title":"Biological roles and an evolutionary sketch of the GRF-GIF transcriptional complex in plants.","date":"2019","source":"BMB reports","url":"https://pubmed.ncbi.nlm.nih.gov/30885290","citation_count":74,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"15354076","id":"PMC_15354076","title":"Effect of 5-MCA-NAT, a putative melatonin MT3 receptor agonist, on intraocular pressure in glaucomatous monkey eyes.","date":"2004","source":"Journal of glaucoma","url":"https://pubmed.ncbi.nlm.nih.gov/15354076","citation_count":71,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"9295238","id":"PMC_9295238","title":"Expression of MT-3 mRNA in human kidney, proximal tubule cell cultures, and renal cell carcinoma.","date":"1997","source":"Toxicology letters","url":"https://pubmed.ncbi.nlm.nih.gov/9295238","citation_count":71,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"16413543","id":"PMC_16413543","title":"Solution structure and dynamics of human metallothionein-3 (MT-3).","date":"2006","source":"FEBS letters","url":"https://pubmed.ncbi.nlm.nih.gov/16413543","citation_count":66,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"8735628","id":"PMC_8735628","title":"Rat striatal muscarinic receptors coupled to the inhibition of adenylyl cyclase activity: potent block by the selective m4 ligand muscarinic toxin 3 (MT3).","date":"1996","source":"British journal of pharmacology","url":"https://pubmed.ncbi.nlm.nih.gov/8735628","citation_count":63,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"9437661","id":"PMC_9437661","title":"Regulation of metallothionein-III (GIF) mRNA in the brain of patients with Alzheimer disease is not impaired.","date":"1997","source":"Molecular and chemical neuropathology","url":"https://pubmed.ncbi.nlm.nih.gov/9437661","citation_count":62,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"15531549","id":"PMC_15531549","title":"Involvement of membrane-type matrix metalloproteinases (MT-MMPs) in capillary tube formation by human endometrial microvascular endothelial cells: role of MT3-MMP.","date":"2004","source":"The Journal of clinical endocrinology and metabolism","url":"https://pubmed.ncbi.nlm.nih.gov/15531549","citation_count":60,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"9778374","id":"PMC_9778374","title":"Metal-thiolate clusters in the C-terminal domain of human neuronal growth inhibitory factor (GIF).","date":"1998","source":"Biochemistry","url":"https://pubmed.ncbi.nlm.nih.gov/9778374","citation_count":58,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"17222386","id":"PMC_17222386","title":"Increase in fluidity in the membrane of MT3 breast cancer cells correlates with enhanced cell adhesion in vitro and increased lung metastasis in NOD/SCID mice.","date":"2006","source":"Archives of biochemistry and biophysics","url":"https://pubmed.ncbi.nlm.nih.gov/17222386","citation_count":57,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"23207065","id":"PMC_23207065","title":"MT3 melatonin binding site, MT1 and MT2 melatonin receptors are present in oocyte, but only MT1 is present in bovine blastocyst produced in vitro.","date":"2012","source":"Reproductive biology and endocrinology : RB&E","url":"https://pubmed.ncbi.nlm.nih.gov/23207065","citation_count":56,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"15581627","id":"PMC_15581627","title":"Organs from mice deleted for NRH:quinone oxidoreductase 2 are deprived of the melatonin binding site MT3.","date":"2004","source":"FEBS letters","url":"https://pubmed.ncbi.nlm.nih.gov/15581627","citation_count":56,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"2582424","id":"PMC_2582424","title":"Molecular characterization of MT3 antigens by two-dimensional gel electrophoresis, NH2-terminal amino acid sequence analysis, and southern blot analysis.","date":"1985","source":"Proceedings of the National Academy of Sciences of the United States of America","url":"https://pubmed.ncbi.nlm.nih.gov/2582424","citation_count":54,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"16414149","id":"PMC_16414149","title":"New ligands at the melatonin binding site MT(3).","date":"2006","source":"European journal of medicinal chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/16414149","citation_count":54,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"30389722","id":"PMC_30389722","title":"Is There Sufficient Evidence that the Melatonin Binding Site MT Is Quinone Reductase 2?","date":"2018","source":"The Journal of pharmacology and experimental therapeutics","url":"https://pubmed.ncbi.nlm.nih.gov/30389722","citation_count":53,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"21459362","id":"PMC_21459362","title":"A new perspective in Oral health: potential importance and actions of melatonin receptors MT1, MT2, MT3, and RZR/ROR in the oral cavity.","date":"2011","source":"Archives of oral biology","url":"https://pubmed.ncbi.nlm.nih.gov/21459362","citation_count":51,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"6198272","id":"PMC_6198272","title":"Antigen-specific HLA-restricted human T-cell lines. I. An MT3-like restriction determinant distinct from HLA-DR.","date":"1984","source":"Immunogenetics","url":"https://pubmed.ncbi.nlm.nih.gov/6198272","citation_count":48,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"11069294","id":"PMC_11069294","title":"Posttranslational modification of the glycosylation inhibiting factor (GIF) gene product generates bioactive GIF.","date":"2000","source":"Proceedings of the National Academy of Sciences of the United States of America","url":"https://pubmed.ncbi.nlm.nih.gov/11069294","citation_count":47,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"7655350","id":"PMC_7655350","title":"Expression of growth inhibitory factor (GIF) in normal and injured rat brains.","date":"1995","source":"Neurochemistry international","url":"https://pubmed.ncbi.nlm.nih.gov/7655350","citation_count":46,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"33349565","id":"PMC_33349565","title":"GRF-GIF Chimeras Boost Plant Regeneration.","date":"2020","source":"Trends in plant science","url":"https://pubmed.ncbi.nlm.nih.gov/33349565","citation_count":46,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"29352064","id":"PMC_29352064","title":"GIF Transcriptional Coregulators Control Root Meristem Homeostasis.","date":"2018","source":"The Plant cell","url":"https://pubmed.ncbi.nlm.nih.gov/29352064","citation_count":46,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"21539592","id":"PMC_21539592","title":"The M4 muscarinic antagonist MT-3 inhibits myopia in chick: evidence for site of action.","date":"2011","source":"Ophthalmic & physiological optics : the journal of the British College of Ophthalmic Opticians (Optometrists)","url":"https://pubmed.ncbi.nlm.nih.gov/21539592","citation_count":45,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"11738272","id":"PMC_11738272","title":"Transient induction of metallothionein isoform 3 (MT-3), c-fos, c-jun and c-myc in human proximal tubule cells exposed to cadmium.","date":"2002","source":"Toxicology letters","url":"https://pubmed.ncbi.nlm.nih.gov/11738272","citation_count":44,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"11099475","id":"PMC_11099475","title":"Functional characterization of MT3-MMP in transfected MDCK cells: progelatinase A activation and tubulogenesis in 3-D collagen lattice.","date":"2000","source":"FASEB journal : official publication of the Federation of American Societies for Experimental Biology","url":"https://pubmed.ncbi.nlm.nih.gov/11099475","citation_count":42,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"25950480","id":"PMC_25950480","title":"Arachidonic acid promotes skin wound healing through induction of human MSC migration by MT3-MMP-mediated fibronectin degradation.","date":"2015","source":"Cell death & disease","url":"https://pubmed.ncbi.nlm.nih.gov/25950480","citation_count":42,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"28956121","id":"PMC_28956121","title":"Participation of MT3 melatonin receptors in the synergistic effect of melatonin on cytotoxic and apoptotic actions evoked by chemotherapeutics.","date":"2017","source":"Cancer chemotherapy and pharmacology","url":"https://pubmed.ncbi.nlm.nih.gov/28956121","citation_count":42,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"1446057","id":"PMC_1446057","title":"Characterization of two human mammary carcinomas, MT-1 and MT-3, suitable for in vivo testing of ether lipids and their derivatives.","date":"1992","source":"Breast cancer research and treatment","url":"https://pubmed.ncbi.nlm.nih.gov/1446057","citation_count":40,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"15129022","id":"PMC_15129022","title":"Expression of metallothionein isoform 3 (MT-3) determines the choice between apoptotic or necrotic cell death in Cd+2-exposed human proximal tubule cells.","date":"2004","source":"Toxicological sciences : an official journal of the Society of Toxicology","url":"https://pubmed.ncbi.nlm.nih.gov/15129022","citation_count":38,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"2424991","id":"PMC_2424991","title":"Structural relationships between the DR beta 1 and DR beta 2 subunits in DR4, 7, and w9 haplotypes and the DRw53 (MT3) specificity.","date":"1986","source":"Journal of immunology (Baltimore, Md. : 1950)","url":"https://pubmed.ncbi.nlm.nih.gov/2424991","citation_count":38,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"6208273","id":"PMC_6208273","title":"Biochemical and functional evidence that an MT3 supertypic determinant defined by a monoclonal antibody is carried on the DR molecule on HLA-DR7 cell lines.","date":"1984","source":"Journal of immunology (Baltimore, Md. : 1950)","url":"https://pubmed.ncbi.nlm.nih.gov/6208273","citation_count":37,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"15081538","id":"PMC_15081538","title":"Cysteine-dependent immune regulation by TRX and MIF/GIF family proteins.","date":"2004","source":"Immunology letters","url":"https://pubmed.ncbi.nlm.nih.gov/15081538","citation_count":36,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"22164270","id":"PMC_22164270","title":"Membrane-type-3 matrix metalloproteinase (MT3-MMP) functions as a matrix composition-dependent effector of melanoma cell invasion.","date":"2011","source":"PloS one","url":"https://pubmed.ncbi.nlm.nih.gov/22164270","citation_count":36,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"9796998","id":"PMC_9796998","title":"Expression of the membrane-type 3 matrix metalloproteinase (MT3-MMP) in human brain tissues.","date":"1998","source":"Acta neuropathologica","url":"https://pubmed.ncbi.nlm.nih.gov/9796998","citation_count":35,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"26757944","id":"PMC_26757944","title":"Thermodynamics of Pb(ii) and Zn(ii) binding to MT-3, a neurologically important metallothionein.","date":"2016","source":"Metallomics : integrated biometal science","url":"https://pubmed.ncbi.nlm.nih.gov/26757944","citation_count":33,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"22582132","id":"PMC_22582132","title":"Barley metallothioneins: MT3 and MT4 are localized in the grain aleurone layer and show differential zinc binding.","date":"2012","source":"Plant physiology","url":"https://pubmed.ncbi.nlm.nih.gov/22582132","citation_count":33,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"24962166","id":"PMC_24962166","title":"Metallothionein III (MT3) is a putative tumor suppressor gene that is frequently inactivated in pediatric acute myeloid leukemia by promoter hypermethylation.","date":"2014","source":"Journal of translational medicine","url":"https://pubmed.ncbi.nlm.nih.gov/24962166","citation_count":33,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"11525948","id":"PMC_11525948","title":"Coordinate expression of membrane type-matrix metalloproteinases-2 and 3 (MT2-MMP and MT3-MMP) and matrix metalloproteinase-2 (MMP-2) in primary and metastatic melanoma cells.","date":"2001","source":"European journal of dermatology : EJD","url":"https://pubmed.ncbi.nlm.nih.gov/11525948","citation_count":32,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"28621422","id":"PMC_28621422","title":"A new role of the membrane-type matrix metalloproteinase 16 (MMP16/MT3-MMP) in neural crest cell migration.","date":"2017","source":"The International journal of developmental biology","url":"https://pubmed.ncbi.nlm.nih.gov/28621422","citation_count":29,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"9482244","id":"PMC_9482244","title":"Brain injury and growth inhibitory factor (GIF)--a minireview.","date":"1998","source":"Neurochemical research","url":"https://pubmed.ncbi.nlm.nih.gov/9482244","citation_count":28,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"36695930","id":"PMC_36695930","title":"GRF-GIF chimeric proteins enhance in vitro regeneration and Agrobacterium-mediated transformation efficiencies of lettuce (Lactuca spp.).","date":"2023","source":"Plant cell reports","url":"https://pubmed.ncbi.nlm.nih.gov/36695930","citation_count":27,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"18826489","id":"PMC_18826489","title":"MT3/QR2 melatonin binding site does not use melatonin as a substrate or a co-substrate.","date":"2008","source":"Journal of pineal research","url":"https://pubmed.ncbi.nlm.nih.gov/18826489","citation_count":27,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"20210850","id":"PMC_20210850","title":"Molecular and cellular pharmacological properties of 5-methoxycarbonylamino-N-acetyltryptamine (MCA-NAT): a nonspecific MT3 ligand.","date":"2010","source":"Journal of pineal research","url":"https://pubmed.ncbi.nlm.nih.gov/20210850","citation_count":26,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"15266722","id":"PMC_15266722","title":"Expression analysis of buckwheat (Fagopyrum esculentum Moench) metallothionein-like gene (MT3) under different stress and physiological conditions.","date":"2004","source":"Journal of plant physiology","url":"https://pubmed.ncbi.nlm.nih.gov/15266722","citation_count":26,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"8869568","id":"PMC_8869568","title":"Patterns of growth inhibitory factor (GIF) and glial fibrillary acidic protein relative level changes differ following left middle cerebral artery occlusion in rats.","date":"1996","source":"Brain research","url":"https://pubmed.ncbi.nlm.nih.gov/8869568","citation_count":24,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"16314047","id":"PMC_16314047","title":"Growth inhibitory factor (GIF) can protect from brain damage due to stab wounds in rat brain.","date":"2005","source":"Neuroscience letters","url":"https://pubmed.ncbi.nlm.nih.gov/16314047","citation_count":24,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"14695536","id":"PMC_14695536","title":"A genetic polymorphism in the coding region of the gastric intrinsic factor gene (GIF) is associated with congenital intrinsic factor deficiency.","date":"2004","source":"Human mutation","url":"https://pubmed.ncbi.nlm.nih.gov/14695536","citation_count":23,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"19264672","id":"PMC_19264672","title":"Conservation and variation of the parapoxvirus GM-CSF-inhibitory factor (GIF) proteins.","date":"2009","source":"The Journal of general virology","url":"https://pubmed.ncbi.nlm.nih.gov/19264672","citation_count":22,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"6197369","id":"PMC_6197369","title":"Identification of the MT3 molecule using two-dimensional gel electrophoresis and alloantisera.","date":"1983","source":"Immunogenetics","url":"https://pubmed.ncbi.nlm.nih.gov/6197369","citation_count":22,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"24242700","id":"PMC_24242700","title":"Metallothionein-3 (MT-3) in the human adrenal cortex and its disorders.","date":"2014","source":"Endocrine pathology","url":"https://pubmed.ncbi.nlm.nih.gov/24242700","citation_count":22,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"1711075","id":"PMC_1711075","title":"Antibody MT3 is reactive with a novel exon B-associated 190-kDa sialic acid-dependent epitope of the leukocyte common antigen complex.","date":"1991","source":"Journal of immunology (Baltimore, Md. : 1950)","url":"https://pubmed.ncbi.nlm.nih.gov/1711075","citation_count":21,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"38923048","id":"PMC_38923048","title":"Use of GRF-GIF chimeras and a ternary vector system to improve maize (Zea mays L.) transformation frequency.","date":"2024","source":"The Plant journal : for cell and molecular biology","url":"https://pubmed.ncbi.nlm.nih.gov/38923048","citation_count":20,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"23402911","id":"PMC_23402911","title":"Gastric intrinsic factor deficiency with combined GIF heterozygous mutations and FUT2 secretor variant.","date":"2013","source":"Biochimie","url":"https://pubmed.ncbi.nlm.nih.gov/23402911","citation_count":20,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"6418807","id":"PMC_6418807","title":"Molecular identifications of HLA-DR4, MT3, and TB21 antigens on HLA-DR4 homozygous B cell lines.","date":"1984","source":"Journal of immunology (Baltimore, Md. : 1950)","url":"https://pubmed.ncbi.nlm.nih.gov/6418807","citation_count":19,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"17419254","id":"PMC_17419254","title":"Overexpression of MT3-MMP in hepatocellular carcinoma correlates with capsular invasion.","date":"2007","source":"Hepato-gastroenterology","url":"https://pubmed.ncbi.nlm.nih.gov/17419254","citation_count":19,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"11750760","id":"PMC_11750760","title":"Different protective roles in vitro of alpha- and beta-domains of growth inhibitory factor (GIF) on neuron injuries caused by oxygen free radicals.","date":"2001","source":"Biochimica et biophysica acta","url":"https://pubmed.ncbi.nlm.nih.gov/11750760","citation_count":19,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"28236273","id":"PMC_28236273","title":"Developmental processes and responses to hormonal stimuli in tea plant (Camellia sinensis) leaves are controlled by GRF and GIF gene families.","date":"2017","source":"Functional & integrative genomics","url":"https://pubmed.ncbi.nlm.nih.gov/28236273","citation_count":19,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"35087553","id":"PMC_35087553","title":"The Rice miR396-GRF-GIF-SWI/SNF Module: A Player in GA Signaling.","date":"2022","source":"Frontiers in plant science","url":"https://pubmed.ncbi.nlm.nih.gov/35087553","citation_count":18,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"22788924","id":"PMC_22788924","title":"Current status and limitations of the newly developed endocytoscope GIF-Y0002 with reference to its diagnostic performance for common esophageal lesions.","date":"2012","source":"Journal of digestive diseases","url":"https://pubmed.ncbi.nlm.nih.gov/22788924","citation_count":18,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"3114153","id":"PMC_3114153","title":"Establishment and characterization of a human IgA-kappa-secreting plasma cell line (MT3).","date":"1987","source":"International journal of cancer","url":"https://pubmed.ncbi.nlm.nih.gov/3114153","citation_count":17,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"9593981","id":"PMC_9593981","title":"Stimulatory effects of 4-methylcatechol, dopamine and levodopa on the expression of metallothionein-III (GIF) mRNA in immortalized mouse brain glial cells (VR-2g).","date":"1998","source":"Brain research","url":"https://pubmed.ncbi.nlm.nih.gov/9593981","citation_count":17,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"10830840","id":"PMC_10830840","title":"Metal-thiolate clusters in neuronal growth inhibitory factor (GIF).","date":"2000","source":"Journal of inorganic biochemistry","url":"https://pubmed.ncbi.nlm.nih.gov/10830840","citation_count":16,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"26031343","id":"PMC_26031343","title":"Melatonin inhibits granulocyte adhesion to ICAM via MT3/QR2 and MT2 receptors.","date":"2015","source":"International immunology","url":"https://pubmed.ncbi.nlm.nih.gov/26031343","citation_count":16,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"36387975","id":"PMC_36387975","title":"Identification and exploration of the GRF and GIF families in maize and foxtail millet.","date":"2022","source":"Physiology and molecular biology of plants : an international journal of functional plant biology","url":"https://pubmed.ncbi.nlm.nih.gov/36387975","citation_count":16,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"27819269","id":"PMC_27819269","title":"Structural basis of GM-CSF and IL-2 sequestration by the viral decoy receptor GIF.","date":"2016","source":"Nature communications","url":"https://pubmed.ncbi.nlm.nih.gov/27819269","citation_count":15,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"20545974","id":"PMC_20545974","title":"Prospective replacement of magnifying endoscopy by a newly developed endocytoscope, the 'GIF-Y0002'.","date":"2010","source":"Diseases of the esophagus : official journal of the International Society for Diseases of the Esophagus","url":"https://pubmed.ncbi.nlm.nih.gov/20545974","citation_count":15,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"37328802","id":"PMC_37328802","title":"Whole-genome identification and expression profiling of growth-regulating factor (GRF) and GRF-interacting factor (GIF) gene families in Panax ginseng.","date":"2023","source":"BMC genomics","url":"https://pubmed.ncbi.nlm.nih.gov/37328802","citation_count":15,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"2431513","id":"PMC_2431513","title":"A human monoclonal antibody to an HLA-DRw53 (MT3)-like epitope on class II antigens.","date":"1986","source":"Tissue antigens","url":"https://pubmed.ncbi.nlm.nih.gov/2431513","citation_count":14,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"29698629","id":"PMC_29698629","title":"Ag-NPs induce apoptosis, mitochondrial damages and MT3/OSGIN2 expression changes in an in vitro model of human dental-pulp-stem-cells-derived neurons.","date":"2018","source":"Neurotoxicology","url":"https://pubmed.ncbi.nlm.nih.gov/29698629","citation_count":14,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"30516222","id":"PMC_30516222","title":"Pb(ii) binding to the brain specific mammalian metallothionein isoform MT3 and its isolated αMT3 and βMT3 domains.","date":"2019","source":"Metallomics : integrated biometal science","url":"https://pubmed.ncbi.nlm.nih.gov/30516222","citation_count":13,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"29413112","id":"PMC_29413112","title":"Expression and immunolocalization of metallothioneins MT1, MT2 and MT3 in rat nephron.","date":"2017","source":"Journal of trace elements in medicine and biology : organ of the Society for Minerals and Trace Elements (GMS)","url":"https://pubmed.ncbi.nlm.nih.gov/29413112","citation_count":13,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"6199337","id":"PMC_6199337","title":"Identification of three class II antigens, DR7, MB2, and MT3, from a homozygous human cell line.","date":"1984","source":"Human immunology","url":"https://pubmed.ncbi.nlm.nih.gov/6199337","citation_count":13,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"17182118","id":"PMC_17182118","title":"Facilitatory effect of the intra-hippocampal pre-test administration of MT3 in the inhibitory avoidance task.","date":"2006","source":"Behavioural brain research","url":"https://pubmed.ncbi.nlm.nih.gov/17182118","citation_count":13,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"29196321","id":"PMC_29196321","title":"MT3-MMP Promotes Excitatory Synapse Formation by Promoting Nogo-66 Receptor Ectodomain Shedding.","date":"2017","source":"The Journal of neuroscience : the official journal of the Society for Neuroscience","url":"https://pubmed.ncbi.nlm.nih.gov/29196321","citation_count":12,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"19548083","id":"PMC_19548083","title":"Inhibition of pulmonary metastasis in a human MT3 breast cancer xenograft model by dual liposomes preventing intravasal fibrin clot formation.","date":"2009","source":"Breast cancer research and treatment","url":"https://pubmed.ncbi.nlm.nih.gov/19548083","citation_count":12,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"25310574","id":"PMC_25310574","title":"The Muscarinic Antagonist MT3 Distinguishes Between Form Deprivation- and Negative Lens-Induced Myopia in Chicks.","date":"2014","source":"Current eye research","url":"https://pubmed.ncbi.nlm.nih.gov/25310574","citation_count":11,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"6205988","id":"PMC_6205988","title":"The MT3 specificity resides on a novel human class II antigen distinct from the HLA-DR antigen and DC-like antigen.","date":"1984","source":"Immunogenetics","url":"https://pubmed.ncbi.nlm.nih.gov/6205988","citation_count":11,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"35075546","id":"PMC_35075546","title":"Bioreduction and bioremoval of hexavalent chromium by genetically engineered strains (Escherichia coli MT2A and Escherichia coli MT3).","date":"2022","source":"World journal of microbiology & biotechnology","url":"https://pubmed.ncbi.nlm.nih.gov/35075546","citation_count":10,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"32512576","id":"PMC_32512576","title":"miR-325-3p Overexpression Inhibits Proliferation and Metastasis of Bladder Cancer Cells by Regulating MT3.","date":"2020","source":"Medical science monitor : international medical journal of experimental and clinical research","url":"https://pubmed.ncbi.nlm.nih.gov/32512576","citation_count":10,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"6436378","id":"PMC_6436378","title":"Identification of the MT3 molecule from HLA-DR4, 7, and w9 homozygous cell lines.","date":"1984","source":"Journal of immunology (Baltimore, Md. : 1950)","url":"https://pubmed.ncbi.nlm.nih.gov/6436378","citation_count":10,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"16609697","id":"PMC_16609697","title":"Cloning and developmental characterization of Xenopus laevis membrane type-3 matrix metalloproteinase (MT3-MMP).","date":"2006","source":"Biochemistry and cell biology = Biochimie et biologie cellulaire","url":"https://pubmed.ncbi.nlm.nih.gov/16609697","citation_count":10,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"30556998","id":"PMC_30556998","title":"Structural Basis for the Interaction and Processing of β-Lactam Antibiotics by l,d-Transpeptidase 3 (LdtMt3) from Mycobacterium tuberculosis.","date":"2018","source":"ACS infectious diseases","url":"https://pubmed.ncbi.nlm.nih.gov/30556998","citation_count":10,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"17762829","id":"PMC_17762829","title":"[Melatonin binding site MT3 is QR2: state of the art].","date":"2007","source":"Journal de la Societe de biologie","url":"https://pubmed.ncbi.nlm.nih.gov/17762829","citation_count":10,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"21377769","id":"PMC_21377769","title":"Design and synthesis of naphthalenic derivatives as new ligands at the melatonin binding site MT3.","date":"2011","source":"European journal of medicinal chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/21377769","citation_count":10,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"39060385","id":"PMC_39060385","title":"Genome-wide identification and expression profiling of growth‑regulating factor (GRF) and GRF‑interacting factor (GIF) gene families in chickpea and pigeonpea.","date":"2024","source":"Scientific reports","url":"https://pubmed.ncbi.nlm.nih.gov/39060385","citation_count":10,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"12477932","id":"PMC_12477932","title":"Generation and initial analysis of more than 15,000 full-length human and mouse cDNA sequences.","date":"2002","source":"Proceedings of the National Academy of Sciences of the United States of America","url":"https://pubmed.ncbi.nlm.nih.gov/12477932","citation_count":1479,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"21873635","id":"PMC_21873635","title":"Phylogenetic-based propagation of functional annotations within the Gene Ontology consortium.","date":"2011","source":"Briefings in bioinformatics","url":"https://pubmed.ncbi.nlm.nih.gov/21873635","citation_count":656,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"1873033","id":"PMC_1873033","title":"The growth inhibitory factor that is deficient in the Alzheimer's disease brain is a 68 amino acid metallothionein-like protein.","date":"1991","source":"Neuron","url":"https://pubmed.ncbi.nlm.nih.gov/1873033","citation_count":622,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"1631128","id":"PMC_1631128","title":"MT-III, a brain-specific member of the metallothionein gene family.","date":"1992","source":"Proceedings of the National Academy of Sciences of the United States of America","url":"https://pubmed.ncbi.nlm.nih.gov/1631128","citation_count":544,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"15489334","id":"PMC_15489334","title":"The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC).","date":"2004","source":"Genome research","url":"https://pubmed.ncbi.nlm.nih.gov/15489334","citation_count":438,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"11226237","id":"PMC_11226237","title":"Zinc metallothionein imported into liver mitochondria modulates respiration.","date":"2001","source":"Proceedings of the National Academy of Sciences of the United States of America","url":"https://pubmed.ncbi.nlm.nih.gov/11226237","citation_count":204,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"20974010","id":"PMC_20974010","title":"Roles of zinc and metallothionein-3 in oxidative stress-induced lysosomal dysfunction, cell death, and autophagy in neurons and astrocytes.","date":"2010","source":"Molecular brain","url":"https://pubmed.ncbi.nlm.nih.gov/20974010","citation_count":180,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"8751715","id":"PMC_8751715","title":"The functional significance of brain metallothioneins.","date":"1996","source":"FASEB journal : official publication of the Federation of American Societies for Experimental Biology","url":"https://pubmed.ncbi.nlm.nih.gov/8751715","citation_count":164,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"1464312","id":"PMC_1464312","title":"Molecular cloning of human growth inhibitory factor cDNA and its down-regulation in Alzheimer's disease.","date":"1992","source":"The EMBO journal","url":"https://pubmed.ncbi.nlm.nih.gov/1464312","citation_count":163,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"12539042","id":"PMC_12539042","title":"HIV-1 Tat reprograms immature dendritic cells to express chemoattractants for activated T cells and macrophages.","date":"2003","source":"Nature medicine","url":"https://pubmed.ncbi.nlm.nih.gov/12539042","citation_count":161,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"18029348","id":"PMC_18029348","title":"Toward a confocal subcellular atlas of the human proteome.","date":"2007","source":"Molecular & cellular proteomics : MCP","url":"https://pubmed.ncbi.nlm.nih.gov/18029348","citation_count":114,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"9655243","id":"PMC_9655243","title":"Expression of the gene encoding metallothionein-3 in organs of the reproductive system.","date":"1998","source":"DNA and cell biology","url":"https://pubmed.ncbi.nlm.nih.gov/9655243","citation_count":102,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"12058024","id":"PMC_12058024","title":"Growth inhibitory factor prevents neurite extension and the death of cortical neurons caused by high oxygen exposure through hydroxyl radical scavenging.","date":"2002","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/12058024","citation_count":101,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"21044950","id":"PMC_21044950","title":"Genome-wide YFP fluorescence complementation screen identifies new regulators for telomere signaling in human cells.","date":"2010","source":"Molecular & cellular proteomics : MCP","url":"https://pubmed.ncbi.nlm.nih.gov/21044950","citation_count":93,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"28538697","id":"PMC_28538697","title":"Mammalian Metallothionein-3: New Functional and Structural Insights.","date":"2017","source":"International journal of molecular sciences","url":"https://pubmed.ncbi.nlm.nih.gov/28538697","citation_count":80,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"11994011","id":"PMC_11994011","title":"Brain-specific metallothionein-3 has higher metal-binding capacity than ubiquitous metallothioneins and binds metals noncooperatively.","date":"2002","source":"Biochemistry","url":"https://pubmed.ncbi.nlm.nih.gov/11994011","citation_count":75,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"18206644","id":"PMC_18206644","title":"PCR arrays identify metallothionein-3 as a highly hypoxia-inducible gene in human adipocytes.","date":"2008","source":"Biochemical and biophysical research communications","url":"https://pubmed.ncbi.nlm.nih.gov/18206644","citation_count":71,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"10517878","id":"PMC_10517878","title":"Metallothionein isoform 3 expression in the human prostate and cancer-derived cell lines.","date":"1999","source":"The Prostate","url":"https://pubmed.ncbi.nlm.nih.gov/10517878","citation_count":57,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"15342556","id":"PMC_15342556","title":"Sequence comparison of human and mouse genes reveals a homologous block structure in the promoter regions.","date":"2004","source":"Genome research","url":"https://pubmed.ncbi.nlm.nih.gov/15342556","citation_count":57,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"18554677","id":"PMC_18554677","title":"Metallothionein-III protects against 6-hydroxydopamine-induced oxidative stress by increasing expression of heme oxygenase-1 in a PI3K and ERK/Nrf2-dependent manner.","date":"2008","source":"Toxicology and applied pharmacology","url":"https://pubmed.ncbi.nlm.nih.gov/18554677","citation_count":57,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"18208603","id":"PMC_18208603","title":"Differential expression of metallothioneins (MTs) 1, 2, and 3 in response to zinc treatment in human prostate normal and malignant cells and tissues.","date":"2008","source":"Molecular cancer","url":"https://pubmed.ncbi.nlm.nih.gov/18208603","citation_count":55,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"12383939","id":"PMC_12383939","title":"Protective effect of metallothionein-III on DNA damage in response to reactive oxygen species.","date":"2002","source":"Biochimica et biophysica acta","url":"https://pubmed.ncbi.nlm.nih.gov/12383939","citation_count":52,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"21320589","id":"PMC_21320589","title":"Redox activity of α-synuclein-Cu is silenced by Zn₇-metallothionein-3.","date":"2011","source":"Free radical biology & medicine","url":"https://pubmed.ncbi.nlm.nih.gov/21320589","citation_count":51,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"16712791","id":"PMC_16712791","title":"Identification of intrahepatic cholangiocarcinoma related genes by comparison with normal liver tissues using expressed sequence tags.","date":"2006","source":"Biochemical and biophysical research communications","url":"https://pubmed.ncbi.nlm.nih.gov/16712791","citation_count":45,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"16036436","id":"PMC_16036436","title":"Screening the metallothionein III gene in sporadic amyotrophic lateral sclerosis.","date":"2005","source":"Amyotrophic lateral sclerosis and other motor neuron disorders : official publication of the World Federation of Neurology, Research Group on Motor Neuron Diseases","url":"https://pubmed.ncbi.nlm.nih.gov/16036436","citation_count":41,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"7677777","id":"PMC_7677777","title":"Modulation of metallothionein-III mRNA content and growth rate of rat C6-glial cells by transfection with human 5-HT1D receptor genes.","date":"1995","source":"Biochemical and biophysical research communications","url":"https://pubmed.ncbi.nlm.nih.gov/7677777","citation_count":41,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"12538345","id":"PMC_12538345","title":"Hypermethylation of metallothionein-3 CpG island in gastric carcinoma.","date":"2003","source":"Carcinogenesis","url":"https://pubmed.ncbi.nlm.nih.gov/12538345","citation_count":40,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"23728617","id":"PMC_23728617","title":"Extracellular HIV-1 viral protein R affects astrocytic glyceraldehyde 3-phosphate dehydrogenase activity and neuronal survival.","date":"2013","source":"Journal of neurovirology","url":"https://pubmed.ncbi.nlm.nih.gov/23728617","citation_count":40,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"12072966","id":"PMC_12072966","title":"A distinct Cu(4)-thiolate cluster of human metallothionein-3 is located in the N-terminal domain.","date":"2002","source":"Journal of biological inorganic chemistry : JBIC : a publication of the Society of Biological Inorganic Chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/12072966","citation_count":38,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"12067712","id":"PMC_12067712","title":"Overexpression of human metallothionein-III prevents hydrogen peroxide-induced oxidative stress in human fibroblasts.","date":"2002","source":"FEBS letters","url":"https://pubmed.ncbi.nlm.nih.gov/12067712","citation_count":37,"is_preprint":false,"source_track":"gene2pubmed"}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":47277,"output_tokens":5316,"usd":0.110785},"stage2":{"model":"claude-opus-4-6","input_tokens":8855,"output_tokens":4135,"usd":0.221475},"total_usd":0.666821,"stage1_batch_id":"msgbatch_01Mgbec4vM6c9vXht7JVJzss","stage2_batch_id":"msgbatch_01JkuuH5RB2BdJNsgnhjbC6s","note":"batch pricing = 50% of standard","round2_stage1":{"model":"claude-sonnet-4-6","input_tokens":60071,"output_tokens":7963,"usd":0.149829},"round2_rules_fired":"R3","round2_stage2":{"model":"claude-opus-4-6","input_tokens":10106,"output_tokens":2905,"usd":0.184732}},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2000,\n      \"finding\": \"The melatonin-binding site MT3 was purified from Syrian hamster kidney by affinity chromatography and identified by tandem mass spectrometry as the hamster homologue of human quinone reductase 2 (QR2/NQO2). Transfection of CHO-K1 cells with the human QR2 gene produced both QR2 enzymatic activity and MT3 melatonin-binding sites, and inhibition data from MT3 binding and QR2 enzymatic activity correlated across tissues and transfected cells.\",\n      \"method\": \"Affinity chromatography purification, tandem mass spectrometry protein sequencing, heterologous transfection, radioligand binding assay, enzyme activity assay\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 — reconstitution by transfection, protein sequencing, multiple orthogonal methods; foundational paper with 438 citations\",\n      \"pmids\": [\"10913150\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2004,\n      \"finding\": \"NQO2 knockout mice lack MT3 melatonin-binding sites in all organs tested, establishing that NQO2 is an obligate component of the MT3 binding site in vivo.\",\n      \"method\": \"NQO2−/− mouse generation, radioligand binding assay with MT3-selective radioligand in organ extracts\",\n      \"journal\": \"FEBS letters\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — genetic knockout with direct binding readout; confirms in vivo identity of MT3 as NQO2\",\n      \"pmids\": [\"15581627\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2005,\n      \"finding\": \"Characterization of the MT3/QR2 binding site using selective ligands revealed two classes of compounds: those that bind within the catalytic site (and inhibit QR2 enzymatic activity) and those that bind outside it (non-inhibitors), demonstrating that the melatonin-binding pocket overlaps with but is not identical to the catalytic site of QR2.\",\n      \"method\": \"Radioligand displacement assay, QR2 enzymatic activity inhibition kinetics, stably transfected QR2-expressing cell line\",\n      \"journal\": \"Biochemical pharmacology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 — enzyme kinetics combined with binding assays, multiple compound series tested\",\n      \"pmids\": [\"16293234\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2008,\n      \"finding\": \"NMR studies of the QR2 catalytic reaction demonstrated that melatonin is neither a substrate nor a co-substrate of QR2 and is not converted to N1-acetyl-N2-formyl-5-methoxykynurenine by catalytically active QR2, refuting the hypothesis that melatonin serves as a co-substrate at MT3.\",\n      \"method\": \"Nuclear magnetic resonance (NMR) spectroscopy of QR2 catalytic reaction with melatonin\",\n      \"journal\": \"Journal of pineal research\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 — direct NMR measurement of enzymatic reaction; single paper but rigorous in vitro biochemistry\",\n      \"pmids\": [\"18826489\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2003,\n      \"finding\": \"MT3-MMP (MMP-16) undergoes autocatalytic processing and ectodomain shedding on the cell surface. TIMP-3 is a high-affinity inhibitor of MT3-MMP (Ki = 0.008 nM) compared with MT1-MMP (Ki = 0.16 nM). MT3-MMP requires TIMP-2 for full pro-MMP-2 activation, and affinity chromatography demonstrated trimolecular complex formation between pro-MMP-2, the catalytic domain of MT3-MMP, and TIMP-2 or TIMP-3.\",\n      \"method\": \"Inhibition kinetics, mutant enzyme studies, affinity chromatography, cell surface activity assays\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 — in vitro kinetics, reconstituted trimolecular complex, mutagenesis; multiple orthogonal methods\",\n      \"pmids\": [\"14681236\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1997,\n      \"finding\": \"MT3-MMP activates progelatinase A (pro-MMP-2) to its mature form when expressed in COS-7 cells; a transmembrane-domainless variant (MT3-MMP-del) produces only the intermediate form, demonstrating that the transmembrane domain is required for complete maturation of MMP-2. Both forms hydrolyze gelatin and casein.\",\n      \"method\": \"cDNA cloning, transfection in COS-7 cells, zymography/substrate degradation assays\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — transfection with domain-deletion mutant and functional readout; multiple substrate assays\",\n      \"pmids\": [\"9092507\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2000,\n      \"finding\": \"In MDCK cells, overexpression of wild-type MT3-MMP (but not its catalytically inactive mutant) enhances cell growth and tubulogenesis in 3-D collagen gels independently of progelatinase A, demonstrating a direct proteolytic function of MT3-MMP in ECM remodeling and cell invasion.\",\n      \"method\": \"Stable transfection, catalytic mutant, 3-D collagen gel tubulogenesis assay\",\n      \"journal\": \"FASEB journal\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — catalytically dead mutant control, functional rescue; clean mechanistic attribution\",\n      \"pmids\": [\"11099475\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2003,\n      \"finding\": \"MT1-MMP and MT3-MMP are both internalized through early endosomes to the trans-Golgi network and recycled back to the cell surface within 60 min via the same vesicles. The carboxyl-terminal DKV582 sequence of MT1-MMP is required for recycling, and co-expressed MT1-MMP and MT3-MMP traffic together throughout the process.\",\n      \"method\": \"Live-cell imaging, immunofluorescence, vesicle co-localization, carboxyl-terminal deletion/mutation analysis\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — direct localization experiment with functional consequence (recycling motif identified), co-trafficking demonstrated\",\n      \"pmids\": [\"14665622\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2011,\n      \"finding\": \"In melanoma cells, MT3-MMP interacts with MT1-MMP in membrane complexes and reduces MT1-MMP cell surface expression, thereby inhibiting MT1-MMP-driven collagen invasion while promoting fibrin-matrix invasion as a potent fibrinolytic enzyme.\",\n      \"method\": \"Co-immunoprecipitation (membrane complex), stable gene silencing (shRNA), overexpression, 3-D invasion assays in collagen and fibrin matrices\",\n      \"journal\": \"PloS one\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — reciprocal functional assays, protein interaction demonstrated, loss-of-function and gain-of-function with defined phenotype\",\n      \"pmids\": [\"22164270\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"MT3-MMP promotes excitatory synapse formation in cortical neurons by shedding the ectodomain of Nogo-66 receptor (NgR1); MT3-MMP loss-of-function impairs excitatory synapse development in vitro and in vivo, and introduction of the shed NgR1 ectodomain rescues and accelerates synaptogenesis.\",\n      \"method\": \"Loss-of-function (genetic knockout/knockdown), in vitro and in vivo synapse formation assays, substrate identification (NgR1 shedding), rescue experiment with shed ectodomain\",\n      \"journal\": \"The Journal of neuroscience\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — KO with defined phenotype, substrate identified, rescue with ectodomain; multiple orthogonal approaches\",\n      \"pmids\": [\"29196321\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"MT3-MMP mediates fibronectin degradation downstream of GPR40/PI3K/mTORC2/Akt/PKCζ/p38 MAPK/Sp1 signaling in arachidonic acid-stimulated human mesenchymal stem cells, promoting cell migration; MT3-MMP silencing abolishes both fibronectin degradation and AA-stimulated motility.\",\n      \"method\": \"siRNA knockdown, Western blotting, migration assay, signaling pathway inhibitors, wound model\",\n      \"journal\": \"Cell death & disease\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — KD with defined biochemical and phenotypic readout, pathway placement by inhibitor series; single lab\",\n      \"pmids\": [\"25950480\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2004,\n      \"finding\": \"MT3-MMP is required for capillary tube formation by human endometrial microvascular endothelial cells (hEMVECs) in fibrin/collagen matrix; anti-MT3-MMP IgG partially inhibited tube formation, and TIMP-3 (which preferentially inhibits MT3-MMP) blocked tube formation in hEMVECs but not in foreskin endothelial cells.\",\n      \"method\": \"Blocking antibody, adenoviral TIMP overexpression, 3-D tube formation assay, immunohistochemistry\",\n      \"journal\": \"The Journal of clinical endocrinology and metabolism\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2-3 — functional blocking with antibody and TIMP, specific inhibitor profile linking MT3-MMP to angiogenesis\",\n      \"pmids\": [\"15531549\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"MT3-MMP (MMP16) is expressed in cranial neural crest cells (NCCs) in avian embryos; knockdown inhibits NCC migration, recombinant MMP16 rescues migration, and excess MMP16 enhances EMT with degradation of laminin and N-cadherin at the dorsal neural tube.\",\n      \"method\": \"In situ hybridization, immunohistochemistry, morpholino/siRNA knockdown, rescue with recombinant protein, substrate degradation analysis\",\n      \"journal\": \"The International journal of developmental biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — loss-of-function with defined phenotype and rescue; substrate degradation identified; ortholog in chick embryo\",\n      \"pmids\": [\"28621422\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2009,\n      \"finding\": \"The 5'-UTR of MT3-MMP mRNA contains a 20-nt G-rich sequence (M3Q) that forms an extremely stable intramolecular RNA G-quadruplex; this structure represses translation of a downstream reporter gene by more than half in eukaryotic cells.\",\n      \"method\": \"Circular dichroism spectroscopy, RNase T1 enzymatic footprinting, dual luciferase reporter assay, thermal melting analysis\",\n      \"journal\": \"Biochemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 — structural characterization combined with functional reporter assay; multiple orthogonal methods in one study\",\n      \"pmids\": [\"19397366\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"The cationic porphyrin TmPyP4 unfolds the M3Q G-quadruplex in MT3-MMP 5'-UTR RNA and relieves its translational repression in a G-quadruplex-dependent manner (mutated construct unaffected), as demonstrated by CD, 1D 1H NMR, native gel electrophoresis, and dual reporter assay.\",\n      \"method\": \"UV spectroscopy, circular dichroism, 1D 1H NMR, native gel electrophoresis, dual luciferase reporter assay\",\n      \"journal\": \"Nucleic acids research\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 — structure-function validated by multiple spectroscopic methods and functional reporter with mutant control\",\n      \"pmids\": [\"22266651\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2006,\n      \"finding\": \"The solution structure of the alpha-domain of human MT-3 (residues 32-68) was determined by multinuclear multidimensional NMR spectroscopy; the protein forms two metal-thiolate clusters (beta-domain N-terminal, alpha-domain C-terminal), the alpha-domain fold is similar to mouse MT-3 but has a longer acidic hexapeptide insertion loop, and backbone dynamics show similar internal motion in both domains.\",\n      \"method\": \"Multinuclear multidimensional NMR spectroscopy, molecular dynamics simulated annealing\",\n      \"journal\": \"FEBS letters\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 — NMR solution structure with backbone dynamics; direct structural determination\",\n      \"pmids\": [\"16413543\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1998,\n      \"finding\": \"Spectroscopic studies on the C-terminal alpha-domain of human MT-3/GIF (residues 32-68) showed formation of Cu4S8-9 and Cu6S11 clusters with Cu(I), and a well-defined M4S11 cluster with Zn(II)/Cd(II) ions in which each metal is tetrahedrally coordinated by cysteine thiolates; 113Cd NMR revealed conformational flexibility of this domain.\",\n      \"method\": \"Electronic absorption, circular dichroism, magnetic circular dichroism (MCD), luminescence spectroscopy, 113Cd NMR spectroscopy\",\n      \"journal\": \"Biochemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 — multiple spectroscopic methods characterizing metal-thiolate cluster stoichiometry and geometry in vitro\",\n      \"pmids\": [\"9778374\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"Isothermal titration calorimetry showed that Pb2+ binding to MT-3 is thermodynamically favorable, displacing Zn2+ from Zn7MT-3 with similar free energy changes per site; metal extraction occurs in a tri-phasic process indicating three populations with different thermodynamics, and Pb2+ remains bound for longer periods than Zn2+ in the intact protein.\",\n      \"method\": \"Isothermal titration calorimetry (ITC), EDTA chelation measurements, circular dichroism\",\n      \"journal\": \"Metallomics : integrated biometal science\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 — quantitative thermodynamic characterization by ITC with multiple metal conditions\",\n      \"pmids\": [\"26757944\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2004,\n      \"finding\": \"Stable transfection of MT-3 into HK-2 proximal tubule cells (which normally lack MT-3) increased sensitivity to Cd2+-induced cytotoxicity and shifted the mechanism of cell death from apoptosis to necrosis, demonstrating that MT-3 expression determines the mode of cadmium-induced cell death.\",\n      \"method\": \"Stable transfection, cytotoxicity assays, apoptosis/necrosis discrimination assays\",\n      \"journal\": \"Toxicological sciences\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — clean gain-of-function with defined mechanistic phenotype (apoptosis vs necrosis switch); single lab\",\n      \"pmids\": [\"15129022\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2001,\n      \"finding\": \"In vitro studies showed that both full-length GIF/MT-3 and its isolated alpha-domain protect cortical neurons and PC12 cells from beta-amyloid 25-35 cytotoxicity, and that the alpha-domain has greater ability to scavenge hydroxyl radicals than the beta-domain as measured by EPR and cytochrome C/Vitamin C radical generating system.\",\n      \"method\": \"Cell survival assay, electron paramagnetic resonance (EPR) spectroscopy, radical scavenging assay\",\n      \"journal\": \"Biochimica et biophysica acta\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — in vitro functional assay with domain dissection and EPR readout; single lab, moderate evidence\",\n      \"pmids\": [\"11750760\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"Melatonin inhibits integrin-mediated granulocyte adhesion to ICAM via MT3/QR2 receptor on granulocytes; MT2 receptor mediates inhibition of fMLP-induced CD18 upregulation, while MT3/QR2 and MT2 together mediate inhibition of granulocyte adhesion. Melatonin increases expression of its MT3/QR2 receptor on granulocytes.\",\n      \"method\": \"Flow cytometry (CD18, receptor expression), adhesion assay to ICAM-coated plates, receptor-selective antagonists, peritoneal infiltration model in mice\",\n      \"journal\": \"International immunology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 — pharmacological dissection with antagonists; receptor identified on granulocytes; single lab\",\n      \"pmids\": [\"26031343\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"Overexpression of MT3 (metallothionein-3) in AML cells inhibited proliferation and induced apoptosis; PCR array identified FOXO1 as a dysregulated gene downstream of MT3 overexpression, suggesting MT3 acts as a tumor suppressor in AML partly through FOXO1-related pathways.\",\n      \"method\": \"Lentiviral overexpression, Annexin V apoptosis assay, proliferation assay, real-time PCR array\",\n      \"journal\": \"Journal of translational medicine\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 — overexpression phenotype with pathway suggestion but no direct mechanistic validation of FOXO1 link\",\n      \"pmids\": [\"24962166\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"MT3 refers to multiple distinct proteins depending on context: (1) the melatonin binding site MT3, purified and identified as NQO2/quinone reductase 2, which binds melatonin at or near its catalytic site but does not use melatonin as a substrate or co-substrate, and whose absence abolishes MT3 binding in vivo; (2) metallothionein-3 (MT-3/GIF), a brain-enriched cysteine-rich metal-binding protein that forms Cu- and Zn-thiolate clusters in distinct N-terminal (β) and C-terminal (α) domains, inhibits neuronal growth, acts as a reactive oxygen species scavenger, binds toxic metals including Pb2+ and Cd2+, and can shift cadmium-induced cell death from apoptosis to necrosis; and (3) MT3-MMP (MMP-16), a membrane-anchored metalloproteinase that activates pro-MMP-2 via trimolecular complex formation with TIMP-2/-3, is inhibited preferentially by TIMP-3, is recycled through the trans-Golgi network in complex with MT1-MMP, modulates MT1-MMP surface expression through membrane complex formation, promotes fibrin matrix invasion and angiogenesis, sheds the NgR1 ectodomain to drive excitatory synaptogenesis, and whose 5'-UTR contains an unusually stable G-quadruplex that represses its own translation.\"\n}\n```\n\n--- ROUND 2 (R2/R3, augmented corpus) ---\n\nLooking at the corpus, I need to identify which papers are about the canonical human MT3 gene (Metallothionein-3, also known as GIF/neuronal growth inhibitory factor, gene symbol MT3, a brain-specific metallothionein).\n\n**Classification:**\n\nThe corpus contains multiple \"MT3\" symbols referring to different genes/proteins:\n1. **MT3 = Metallothionein-3 (GIF/neuronal growth inhibitory factor)** — the canonical target → KEEP\n2. **MT3 = Melatonin binding site MT3 (= QR2/NQO2)** — alias collision, different protein → EXCLUDE\n3. **MT3-MMP (MMP16/membrane-type 3 matrix metalloproteinase)** — different protein → EXCLUDE\n4. **MT3 = HLA supertypic specificity (MHC class II antigen)** — different context → EXCLUDE\n5. **MT3 muscarinic toxin 3** — different protein → EXCLUDE\n6. **GIF = plant GRF-interacting factor** — plant protein, symbol collision → EXCLUDE\n7. **GIF = gastric intrinsic factor** — alias collision → EXCLUDE\n8. **GIF = parapoxvirus GM-CSF inhibitory factor** — different organism/protein → EXCLUDE\n9. **MazF-mt3 from M. tuberculosis** — different organism → EXCLUDE\n10. **MT3 breast cancer cell line** — cell line name, not the gene → EXCLUDE\n11. **LdtMt3 from M. tuberculosis** — different organism → EXCLUDE\n12. **Barley MT3/MT4** — plant metallothionein, different organism (SYMBOL COLLISION with incompatible function context) → need to assess. Barley MT3 is a plant metallothionein, functionally different from human MT3 → EXCLUDE\n13. **Buckwheat MT3** — plant → EXCLUDE\n14. **E. coli MT3 (engineered strain)** — not the gene → EXCLUDE\n\n**KEPT papers** (about canonical human/mammalian MT3/GIF metallothionein-3):\n\nFrom retrieved papers:\n- [4] PMID:7953645 — MT-III/GIF in AD brain, neuronal inhibitory activity, recombinant MT-III specificity\n- [21] PMID:16413543 — NMR solution structure of human MT-3 alpha-domain\n- [25] PMID:9778374 — Metal-thiolate clusters in C-terminal domain of human GIF\n- [39] PMID:11738272 — MT-3 expression in proximal tubule cells, cadmium response\n- [44] PMID:15129022 — MT-3 expression determines apoptotic vs necrotic death in Cd-exposed cells\n- [50] PMID:26757944 — ITC thermodynamics of Pb/Zn binding to MT-3\n- [52] PMID:24962166 — MT3 as tumor suppressor in AML, promoter hypermethylation, apoptosis via FOXO1\n- [55] PMID:9482244 — GIF/MT-III in brain injury, reactive astrocytes\n- [60] PMID:8869568 — GIF in rat brain after cerebral artery occlusion\n- [61] PMID:16314047 — GIF protects from brain damage in stab wound model\n- [65] PMID:24242700 — MT-3 in adrenal cortex, angiotensin-II/forskolin induction\n- [71] PMID:11750760 — Alpha/beta domains of GIF protection against ROS, neuron injuries\n- [76] PMID:9593981 — MT-III mRNA induction by catecholamines in glial cells\n- [77] PMID:10830840 — Metal-thiolate clusters in GIF beta and alpha domains\n- [84] PMID:29698629 — MT3 and OSGIN2 expression changes in Ag-NP-treated neurons\n- [85] PMID:30516222 — Pb(II) binding to MT3 and its domains\n- [86] PMID:29413112 — MT3 localization in rat nephron nuclei\n- [93] PMID:35075546 — MT2A and MT3 in E. coli for Cr removal (engineered, not canonical function) → EXCLUDE (this is about engineered E. coli expressing human MT3 for bioremediation, not mechanistic findings about MT3 function per se)\n- [94] PMID:32512576 — miR-325-3p targeting MT3 in bladder cancer, EMT\n\nFrom gene2pubmed papers:\n- [3] PMID:1873033 — Original purification of GIF, 68 aa metallothionein-like, inhibits neuron survival\n- [4] PMID:1631128 — MT-III cloning, brain-specific, no metal induction\n- [7] PMID:20974010 — MT-3 roles in lysosomal dysfunction, autophagy, zinc dyshomeostasis\n- [8] PMID:8751715 — Functional significance of brain MTs, MT-III in zinc-containing neurons\n- [9] PMID:1464312 — Molecular cloning of human GIF cDNA, neuronal growth inhibition\n- [12] PMID:9655243 — MT-3 expression in reproductive organs, androgen regulation\n- [13] PMID:12058024 — GIF prevents neurite extension and neuronal death via hydroxyl radical scavenging\n- [15] PMID:28538697 — Review: MT-3 structure/function, Cu/Zn clusters, protects from Cu-amyloid toxicity\n- [16] PMID:11994011 — MT-3 binds metals noncooperatively, higher metal-binding capacity\n- [17] PMID:18206644 — MT-3 highly hypoxia-inducible in adipocytes via HIF-1\n- [20] PMID:18554677 — MT-III protects against 6-OHDA via PI3K/ERK/Nrf2/HO-1\n- [22] PMID:12383939 — MT-III protects DNA from ROS, sulfhydryl groups involved\n- [23] PMID:21320589 — Zn7MT-3 silences redox activity of α-Syn-Cu via Cu(II) removal\n- [26] PMID:7677777 — MT-III mRNA inversely correlated with mitogenic activity in glial cells\n- [27] PMID:12538345 — MT-3 CpG island hypermethylation in gastric carcinoma\n- [29] PMID:12072966 — Cu4-thiolate cluster in N-terminal beta-domain of MT-3\n- [30] PMID:12067712 — MT-III overexpression protects fibroblasts from H2O2 oxidative stress\n\nNow extracting mechanistic discoveries from KEPT papers:\n\n```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 1991,\n      \"finding\": \"MT3 (GIF) was purified from normal human brain as a 68 amino acid metallothionein-like protein with ~70% identity to MT-II, containing a unique 6 amino acid insert in the C-terminal region; it directly inhibited survival and neurite formation of cortical neurons in vitro, and was markedly reduced in a distinct subset of astrocytes in Alzheimer's disease cortex.\",\n      \"method\": \"Protein purification, amino acid sequencing, in vitro neuronal survival assay, immunohistochemistry\",\n      \"journal\": \"Neuron\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 — original purification with sequence determination and functional in vitro assay; foundational paper with 622 citations\",\n      \"pmids\": [\"1873033\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1992,\n      \"finding\": \"MT-III gene was cloned and shown to be brain-restricted in expression and to fail to respond to zinc, cadmium, dexamethasone, or bacterial endotoxin in vivo, distinguishing it from MT-I and MT-II; the gene is closely linked to other MT genes on human chromosome 16.\",\n      \"method\": \"Molecular cloning, Northern blot, in vivo metal/hormone challenge experiments\",\n      \"journal\": \"Proceedings of the National Academy of Sciences of the United States of America\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 — cloning with functional characterization, replicated in multiple species; 544 citations\",\n      \"pmids\": [\"1631128\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1992,\n      \"finding\": \"Molecular cloning of human GIF cDNA confirmed it as a new metallothionein family member with nervous-system-exclusive expression; recombinant GIF produced in E. coli inhibited the growth of neonatal rat cortical neurons, and GIF mRNA was drastically decreased in AD brains by Northern blot.\",\n      \"method\": \"cDNA cloning, recombinant protein expression in E. coli, neuronal growth inhibition assay, Northern blot\",\n      \"journal\": \"The EMBO journal\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 — recombinant protein with functional assay, replicated finding; 163 citations\",\n      \"pmids\": [\"1464312\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1994,\n      \"finding\": \"Recombinant MT-III (but not MT-I) specifically inhibited survival of rat cortical neurons in culture when added to brain extract-supplemented cultures, confirming MT-III as a neuron-specific inhibitory factor; however, MT-III protein and mRNA levels were not significantly decreased in AD frontal cortex relative to controls in this study.\",\n      \"method\": \"Recombinant protein addition to neuronal cultures, Western blot, immunoassay\",\n      \"journal\": \"Brain research\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — direct functional assay with recombinant protein and isoform specificity control (MT-I vs MT-III)\",\n      \"pmids\": [\"7953645\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1996,\n      \"finding\": \"MT-III is expressed predominantly in zinc-containing neurons of the hippocampus (not glia), where it functions as a zinc buffer/regulator, and MT-III knockout mice show heightened sensitivity to kainate-induced seizures, establishing a role for MT-III in neuromodulation and zinc homeostasis in vivo.\",\n      \"method\": \"Immunohistochemistry, knockout mouse model, kainate seizure assay\",\n      \"journal\": \"FASEB journal\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — knockout animal phenotype with defined cellular context; 164 citations\",\n      \"pmids\": [\"8751715\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1998,\n      \"finding\": \"Metal-thiolate cluster formation in the C-terminal alpha-domain of human GIF (residues 32-68) was characterized: with Cu(I), two air-sensitive Cu4S8-9 and Cu6S11 clusters form successively; with Zn(II) or Cd(II), a well-defined M4S11 cluster with tetrahedral coordination forms; 113Cd NMR revealed conformational flexibility of this domain.\",\n      \"method\": \"Electronic absorption spectroscopy, CD, MCD, luminescence spectroscopy, 113Cd NMR\",\n      \"journal\": \"Biochemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 — multiple orthogonal spectroscopic methods for structural characterization\",\n      \"pmids\": [\"9778374\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1998,\n      \"finding\": \"MT-3 mRNA expression is not restricted to brain but is also present in rat testis, prostate, epididymis, tongue, ovary, uterus, stomach, heart, and seminal vesicles; prostatic MT-3 mRNA was decreased 75% by orchiectomy and restored by dihydrotestosterone treatment, establishing androgen-dependent regulation of MT-3 in the prostate.\",\n      \"method\": \"Northern blot, in situ hybridization, orchiectomy/DHT replacement experiments\",\n      \"journal\": \"DNA and cell biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — hormone manipulation experiment with defined molecular readout\",\n      \"pmids\": [\"9655243\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2000,\n      \"finding\": \"Native GIF contains 4 Cu(I) and 3 Zn(II) ions in homometallic metal-thiolate clusters; stepwise Cu(I) incorporation into recombinant apo-MT-3 reveals cooperative formation of two Cu4S9 clusters (one per domain) and then Cu6S9 and Cu6S11 clusters in beta and alpha domains of fully metallated Cu12-MT-3; the Cu4 cluster preferentially forms in the N-terminal beta-domain.\",\n      \"method\": \"Electronic absorption, CD, MCD, luminescence spectroscopy, immunochemistry with domain-specific antibodies, limited tryptic digestion\",\n      \"journal\": \"Journal of inorganic biochemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 — multiple complementary spectroscopic and biochemical methods defining cluster localization\",\n      \"pmids\": [\"10830840\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2001,\n      \"finding\": \"MT-3 (zinc metallothionein) imported into liver mitochondria inhibits respiration; this inhibition is caused specifically by the N-terminal beta-domain via zinc delivery to the electron transfer chain; the alpha-domain alone is inactive in this system, and carbamoylation of lysines attenuates import.\",\n      \"method\": \"Mitochondrial import assay, respiratory inhibition measurement, isolated domain experiments, chemical modification\",\n      \"journal\": \"Proceedings of the National Academy of Sciences of the United States of America\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 — reconstituted in vitro assay with domain dissection and chemical modification; 204 citations\",\n      \"pmids\": [\"11226237\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2001,\n      \"finding\": \"The alpha-domain of GIF shows greater capacity to scavenge hydroxyl radicals and eliminate reactive oxygen species than the beta-domain, as demonstrated by EPR spin-trapping; both GIF and its domains protect neurons and PC12 cells from beta-amyloid 25-35 cytotoxicity.\",\n      \"method\": \"EPR spin-trapping, CytC-VitC radical-producing system, neuronal/PC12 cell cytotoxicity assay\",\n      \"journal\": \"Biochimica et biophysica acta\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — in vitro assay with domain comparison, single lab\",\n      \"pmids\": [\"11750760\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2002,\n      \"finding\": \"MT-3 binds Zn2+ and Cd2+ noncooperatively (unlike MT-1/MT-2) and can accommodate more than 7 metal ions; the N-terminal beta-cluster accounts for heterogeneity of metalloforms and has higher metal-transfer potential than the beta-cluster of MT-2, suggesting MT-3 functions as a dynamic zinc buffer in zincergic neurons.\",\n      \"method\": \"Mass spectrometry, pH/stability studies, EDTA competition assay, ultrafiltration\",\n      \"journal\": \"Biochemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 — mass spectrometry with multiple orthogonal analyses, distinct mechanistic property identified\",\n      \"pmids\": [\"11994011\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2002,\n      \"finding\": \"MT-III protects against DNA strand breaks and deoxyribose degradation induced by Fe3+-NTA/H2O2 and scavenges superoxide anion; alkylation of sulfhydryl groups with N-ethylmaleimide abolishes the protective effect, demonstrating that the cysteine thiolate groups are the active moiety for ROS scavenging.\",\n      \"method\": \"Plasmid DNA single-strand break assay, deoxyribose degradation assay, xanthine/xanthine oxidase system, NEM chemical modification\",\n      \"journal\": \"Biochimica et biophysica acta\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 — in vitro assay with active-site chemical modification identifying cysteine thiolates as functional groups\",\n      \"pmids\": [\"12383939\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2002,\n      \"finding\": \"The Cu4-thiolate cluster in MT-3 is located preferentially in the N-terminal beta-domain; using domain-specific antibodies combined with limited tryptic digestion of partially metal-occupied Cu4-MT-3, Cu4S9 cluster was assigned to the beta-domain containing 9 cysteines.\",\n      \"method\": \"Domain-specific antibody immunochemistry, limited tryptic digestion, CD and luminescence spectroscopy\",\n      \"journal\": \"Journal of biological inorganic chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 — domain localization by antibody/digestion combined with spectroscopy\",\n      \"pmids\": [\"12072966\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2002,\n      \"finding\": \"Exogenous GIF (MT-III) prevents neurite extension of cortical neurons in early differentiation and protects differentiated neurons from high-oxygen-induced death; ESR spin-trapping showed GIF at 2-6 µM efficiently scavenges hydroxyl radicals (more effectively than MT-I+II at same concentration) but does not scavenge superoxide or NO; antisense knockdown of GIF promoted neuronal death under high oxygen.\",\n      \"method\": \"Cortical neuron culture, antisense S-oligonucleotide knockdown, ESR spin-trapping with Fenton reaction and H2O2 photolysis\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 — direct functional assay combined with ESR mechanistic analysis and loss-of-function; 101 citations\",\n      \"pmids\": [\"12058024\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2002,\n      \"finding\": \"Stable transfection of human MT-III into GM00637 fibroblasts conferred significant resistance to H2O2-induced cytotoxicity, reduced ROS production, and protected against DNA damage, directly demonstrating MT-III antioxidant function in non-neural cells.\",\n      \"method\": \"Stable transfection, H2O2 challenge, LDH cytotoxicity, ROS measurement, comet assay\",\n      \"journal\": \"FEBS letters\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — clean gain-of-function transfection with defined phenotypic readouts, single lab\",\n      \"pmids\": [\"12067712\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2003,\n      \"finding\": \"CpG island hypermethylation in intron 1 of the MT-3 gene silences its transcription in gastric carcinoma cell lines; treatment with 5-azacytidine (demethylating agent) restored MT-3 mRNA expression, establishing epigenetic regulation of MT-3 as a mechanism for its downregulation in cancer.\",\n      \"method\": \"Bisulfite sequencing, DHPLC methylation analysis, 5-azacytidine treatment, RT-PCR\",\n      \"journal\": \"Carcinogenesis\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — pharmacological demethylation restoring expression, confirmed in multiple cell lines and primary tumors\",\n      \"pmids\": [\"12538345\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2004,\n      \"finding\": \"MT-3 expression in HK-2 (human proximal tubule) cells (stably transfected) sensitized cells to Cd2+-induced cytotoxicity and shifted the mechanism of cell death from apoptosis (no MT-3) to necrosis (with MT-3), demonstrating that MT-3 controls the mode of cell death in response to heavy metal toxicity.\",\n      \"method\": \"Stable transfection of MT-3 into HK-2 cells, Cd2+ cytotoxicity assay, apoptosis/necrosis characterization\",\n      \"journal\": \"Toxicological sciences\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — clean gain-of-function experiment with defined mechanistic endpoint (apoptosis vs. necrosis)\",\n      \"pmids\": [\"15129022\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2006,\n      \"finding\": \"Solution structure of the alpha-domain (residues 32-68) of human MT-3 was determined by multinuclear/multidimensional NMR; the domain forms a metal-thiolate cluster similar in overall fold to mouse MT-3 but with a longer loop in the acidic hexapeptide insertion; backbone dynamics showed the beta-domain has similar internal motion to the alpha-domain though N-terminal residues are more flexible.\",\n      \"method\": \"Multinuclear multidimensional NMR spectroscopy, molecular dynamics simulated annealing\",\n      \"journal\": \"FEBS letters\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 — NMR structure determination with dynamics analysis\",\n      \"pmids\": [\"16413543\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2008,\n      \"finding\": \"MT-III protects dopaminergic SH-SY5Y cells against 6-OHDA-induced oxidative stress through a mechanism involving PI3K and ERK kinase activation, Nrf2 nuclear translocation, and upregulation of heme oxygenase-1 (HO-1); inhibiting PI3K or ERK blocked MT-III-induced HO-1 expression and neuroprotection.\",\n      \"method\": \"Cell viability assay, ROS measurement, kinase inhibitor studies, Nrf2 nuclear fractionation, Western blot for HO-1\",\n      \"journal\": \"Toxicology and applied pharmacology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — pathway dissection with multiple inhibitors and defined signaling readouts, single lab\",\n      \"pmids\": [\"18554677\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2008,\n      \"finding\": \"MT-3 mRNA expression in human adipocytes is dramatically (>600-fold) and rapidly (within 60 min) induced by hypoxia (1% O2) and by hypoxia mimetics (CoCl2, desferrioxamine, DMOG), indicating transcriptional regulation through HIF-1; MT-3 was also induced in preadipocytes and detected in human adipose tissue.\",\n      \"method\": \"PCR arrays, real-time RT-PCR, hypoxia mimetic treatment, preadipocyte cultures\",\n      \"journal\": \"Biochemical and biophysical research communications\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — multiple hypoxia mimetics used, HIF-1 pathway inferred; single lab\",\n      \"pmids\": [\"18206644\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2010,\n      \"finding\": \"MT-3 regulates lysosomal function: in MT-3-null brain cells, lysosome-associated membrane proteins (LAMP-1/-2) and lysosomal enzyme levels are reduced with decreased autophagic flux; under acute oxidative stress, zinc released from MT-3 accumulates in autolysosomes and triggers lysosomal membrane permeabilization leading to cell death; absence of MT-3 reduces zinc-mediated lysosomal damage and decreases acute cell death.\",\n      \"method\": \"MT-3 null cell studies, lysosomal enzyme assays, LAMP protein expression, autophagic flux measurement, oxidative stress challenge\",\n      \"journal\": \"Molecular brain\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — null cell genetic model with defined organelle-level mechanistic readouts; 180 citations\",\n      \"pmids\": [\"20974010\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2011,\n      \"finding\": \"Zn7-MT-3 removes Cu(II) from the α-synuclein-Cu(II) complex through reduction of Cu(II) by thiolate ligands, forming Cu(I)4Zn4MT-3 with an unusual oxygen-stable Cu(I)4-thiolate cluster; this mechanism abolishes α-Syn catalytic oxidase activity, prevents α-Syn oligomerization, hydroxyl radical production, and dopamine oxidation.\",\n      \"method\": \"UV-vis and CD spectroscopy, stopped-flow kinetics, mass spectrometry, ROS detection, α-Syn aggregation assay\",\n      \"journal\": \"Free radical biology & medicine\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 — mechanistic in vitro reconstitution with structural characterization of the Cu(I)4-thiolate cluster product\",\n      \"pmids\": [\"21320589\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"MT3 promoter hypermethylation silences expression in pediatric AML cell lines and patient samples; lentiviral MT3 overexpression in AML cells inhibited proliferation and induced apoptosis; PCR array analysis identified FOXO1 as dysregulated downstream of MT3 overexpression, suggesting FOXO1 as part of the MT3-mediated pro-apoptotic pathway.\",\n      \"method\": \"MSP and bisulfite genomic sequencing, lentiviral overexpression, Annexin V apoptosis assay, RT-PCR array\",\n      \"journal\": \"Journal of translational medicine\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2-3 — gain-of-function with functional readout and downstream pathway gene identified, single lab\",\n      \"pmids\": [\"24962166\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"Isothermal titration calorimetry showed Pb2+ binding to Zn7MT-3 displaces each zinc ion with similar ΔG and ΔH; EDTA chelation studies revealed both Zn and Pb are extracted in a tri-phasic process indicating three binding populations with different thermodynamics; metal binding is entropically favored with an enthalpic penalty reflecting cysteine deprotonation upon thiolate ligation.\",\n      \"method\": \"Isothermal titration calorimetry (ITC), EDTA chelation, CD spectroscopy\",\n      \"journal\": \"Metallomics\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 — rigorous thermodynamic characterization by ITC with multiple metal and structural analyses\",\n      \"pmids\": [\"26757944\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"Comprehensive review and experimental synthesis established that MT-3 possesses distinct Cu/Zn metal-thiolate cluster properties compared to MT-1/MT-2; specifically, Zn7MT-3 (but not MT-1/MT-2) protects neuronal cells from toxicity of Cu(II)-bound amyloids (Aβ, α-Syn) by transmetallation, and the unique acidic hexapeptide insert in the C-terminal domain and the N-terminal extension are structural determinants of its distinct biological activity.\",\n      \"method\": \"Review integrating structural (NMR, spectroscopy) and functional (cell toxicity) data; domain mutagenesis context\",\n      \"journal\": \"International journal of molecular sciences\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — synthesis review citing primary experimental data; 80 citations\",\n      \"pmids\": [\"28538697\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"Pb(II) binding to full-length MT3 is relatively unaffected by pH (stable), whereas isolated alpha and beta fragments interact with Pb(II) in a pH-sensitive manner; mass spectrometry revealed Pb-MT3 complexes persist long-term with intact protein but Pb is eventually released from isolated fragments; Zn(II) displacement by Pb(II) is thermodynamically favorable in both intact MT3 and isolated domains.\",\n      \"method\": \"Spectroscopy, mass spectrometry, isothermal titration calorimetry, pH-dependent binding studies\",\n      \"journal\": \"Metallomics\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 — multiple orthogonal methods (ITC, MS, CD) with domain comparison\",\n      \"pmids\": [\"30516222\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"miR-325-3p directly targets the MT3 3'UTR (confirmed by dual-luciferase reporter assay); MT3 overexpression in bladder cancer T24 cells promotes proliferation, invasion, migration, and EMT (increased MMP9, decreased E-cadherin); miR-325-3p mimics suppress these effects by reducing MT3 levels.\",\n      \"method\": \"Dual-luciferase reporter assay, transwell invasion/migration assay, CCK-8 proliferation assay, Western blot for EMT markers\",\n      \"journal\": \"Medical science monitor\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2-3 — validated miRNA target with gain/loss-of-function and defined molecular readouts, single lab\",\n      \"pmids\": [\"32512576\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"MT3 (metallothionein-3/GIF) is a brain-enriched, 68-amino acid, cysteine-rich metalloprotein organized into N-terminal beta and C-terminal alpha domains that coordinately sequester Cu(I) (preferentially in the beta-domain as a Cu4-thiolate cluster) and Zn(II) (as an M4S11 cluster in the alpha-domain); it functions as a potent hydroxyl radical scavenger via its cysteine thiolates (more effective than MT-I/II), regulates lysosomal integrity and autophagic flux through zinc dynamics, suppresses the redox activity of Cu(II)-amyloid complexes (including α-synuclein-Cu) by transmetallation, inhibits neuronal survival and neurite outgrowth, modulates apoptosis vs. necrosis cell death fate in cadmium toxicity, and is transcriptionally silenced by CpG island hypermethylation in multiple cancers; MT3 expression is androgen-regulated in the prostate and HIF-1-dependent under hypoxia.\"\n}\n```","stage2_raw":"```json\n{\n  \"mechanistic_narrative\": \"The gene symbol MT3 maps to three distinct proteins in the literature: metallothionein-3 (MT-3/GIF), the melatonin-binding site MT3 (identified as NQO2/quinone reductase 2), and MT3-MMP (MMP-16). Metallothionein-3 is a brain-enriched cysteine-rich protein that coordinates Zn(II) and Cu(I) ions in two metal-thiolate cluster domains (β and α); the α-domain forms Cu4–Cu6 and M4S11 clusters, scavenges hydroxyl radicals more effectively than the β-domain, and protects cortical neurons from β-amyloid toxicity [PMID:9778374, PMID:11750760, PMID:16413543]. MT-3 binds Pb²⁺ with thermodynamic favorability comparable to Zn²⁺, and its ectopic expression in renal cells shifts cadmium-induced cell death from apoptosis to necrosis, indicating a role in modulating toxic metal handling and cell death pathways [PMID:26757944, PMID:15129022]. MT3-MMP (MMP-16) is a membrane-type matrix metalloproteinase that activates pro-MMP-2 through TIMP-2-dependent trimolecular complex formation, promotes fibrin-matrix invasion and angiogenesis, drives neural crest cell migration by degrading laminin and N-cadherin, and sheds the NgR1 ectodomain to promote excitatory synaptogenesis; its translation is repressed by an unusually stable 5′-UTR RNA G-quadruplex [PMID:9092507, PMID:14681236, PMID:29196321, PMID:19397366].\",\n  \"teleology\": [\n    {\n      \"year\": 1997,\n      \"claim\": \"Establishing that MT3-MMP is a transmembrane metalloproteinase capable of activating pro-MMP-2 answered whether this newly cloned MMP family member had gelatinase-activating capacity and whether its membrane anchor was functionally required.\",\n      \"evidence\": \"Transfection of full-length and transmembrane-deleted MT3-MMP in COS-7 cells with zymographic readout\",\n      \"pmids\": [\"9092507\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Endogenous substrates beyond pro-MMP-2 not identified\", \"Regulation of MT3-MMP expression unknown\", \"In vivo relevance not tested\"]\n    },\n    {\n      \"year\": 1998,\n      \"claim\": \"Spectroscopic characterization of the MT-3 α-domain metal-thiolate clusters defined the stoichiometry and geometry of Cu(I) and Zn(II)/Cd(II) coordination, establishing the structural basis for MT-3's metal-binding function.\",\n      \"evidence\": \"Electronic absorption, CD, MCD, luminescence, and ¹¹³Cd NMR spectroscopy on recombinant α-domain\",\n      \"pmids\": [\"9778374\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Full-length protein structure not determined\", \"In vivo metal loading stoichiometry unknown\", \"β-domain cluster characterization incomplete\"]\n    },\n    {\n      \"year\": 2000,\n      \"claim\": \"Identification of the melatonin-binding site MT3 as NQO2/quinone reductase 2 resolved the molecular identity of this pharmacological target and established that melatonin binding occurs at or near the QR2 catalytic site.\",\n      \"evidence\": \"Affinity purification from hamster kidney, MS/MS sequencing, heterologous reconstitution in CHO-K1 cells with radioligand binding\",\n      \"pmids\": [\"10913150\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Physiological consequence of melatonin binding to NQO2 not defined\", \"Whether melatonin is a substrate remained unresolved at this point\"]\n    },\n    {\n      \"year\": 2000,\n      \"claim\": \"Demonstration that MT3-MMP catalytic activity directly promotes cell invasion and tubulogenesis in 3-D collagen — independently of MMP-2 activation — established MT3-MMP as a direct ECM-remodeling protease.\",\n      \"evidence\": \"Overexpression of WT vs. catalytically dead MT3-MMP mutant in MDCK cells, 3-D collagen tubulogenesis assay\",\n      \"pmids\": [\"11099475\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Direct ECM substrates not identified\", \"In vivo confirmation lacking\"]\n    },\n    {\n      \"year\": 2001,\n      \"claim\": \"Showing that MT-3's α-domain scavenges hydroxyl radicals and protects neurons from β-amyloid toxicity established a neuroprotective ROS-scavenging function distinct from simple metal sequestration.\",\n      \"evidence\": \"EPR spectroscopy for radical scavenging, cortical neuron and PC12 cell survival assays with domain-dissected constructs\",\n      \"pmids\": [\"11750760\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"In vivo neuroprotection not demonstrated\", \"Mechanism of radical scavenging (direct vs. metal-mediated) not resolved\", \"Relevance to Alzheimer's disease pathology not established\"]\n    },\n    {\n      \"year\": 2003,\n      \"claim\": \"Kinetic and reconstitution studies revealed that TIMP-3 is a picomolar-affinity inhibitor of MT3-MMP and that pro-MMP-2 activation requires formation of a trimolecular complex with TIMP-2 or TIMP-3, defining the regulatory framework for MT3-MMP activity.\",\n      \"evidence\": \"Enzyme inhibition kinetics, affinity chromatography of trimolecular complex, mutant enzyme studies\",\n      \"pmids\": [\"14681236\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"In vivo stoichiometry of the trimolecular complex unknown\", \"Relative contributions of TIMP-2 vs. TIMP-3 in physiological settings unclear\"]\n    },\n    {\n      \"year\": 2003,\n      \"claim\": \"Discovery that MT1-MMP and MT3-MMP co-traffic through early endosomes to the trans-Golgi network and recycle together revealed a shared intracellular itinerary that could regulate their surface availability.\",\n      \"evidence\": \"Live-cell imaging, immunofluorescence co-localization, C-terminal deletion mutant analysis in cultured cells\",\n      \"pmids\": [\"14665622\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Whether MT3-MMP has its own recycling motif not determined\", \"Functional consequence of co-trafficking not tested\"]\n    },\n    {\n      \"year\": 2004,\n      \"claim\": \"NQO2 knockout mice completely lacked MT3 binding sites, providing genetic proof that NQO2 is the sole molecular entity responsible for the MT3 melatonin-binding site in vivo.\",\n      \"evidence\": \"NQO2−/− mice, radioligand binding in organ extracts\",\n      \"pmids\": [\"15581627\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Phenotypic consequences of losing MT3/NQO2 binding not characterized\", \"Whether melatonin binding to NQO2 has signaling output remains unknown\"]\n    },\n    {\n      \"year\": 2004,\n      \"claim\": \"Gain-of-function expression of MT-3 in renal proximal tubule cells shifted cadmium-induced death from apoptosis to necrosis, demonstrating that MT-3 modulates the mode of toxic metal-induced cell death.\",\n      \"evidence\": \"Stable transfection of MT-3 into MT-3-negative HK-2 cells, Cd²⁺ cytotoxicity with apoptosis/necrosis discrimination\",\n      \"pmids\": [\"15129022\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Mechanism of apoptosis-to-necrosis switch not identified\", \"Whether Cd²⁺ binding per se or downstream signaling is responsible unclear\", \"Relevance to in vivo renal toxicity not tested\"]\n    },\n    {\n      \"year\": 2006,\n      \"claim\": \"The NMR solution structure of the human MT-3 α-domain provided the first high-resolution view of the human protein fold, revealing conservation with mouse MT-3 but a distinctive acidic hexapeptide insertion loop.\",\n      \"evidence\": \"Multinuclear multidimensional NMR spectroscopy and simulated annealing on recombinant α-domain\",\n      \"pmids\": [\"16413543\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Full-length MT-3 structure not solved\", \"β-domain structure in human not determined\", \"Structure with bound toxic metals (Pb, Cd) not obtained\"]\n    },\n    {\n      \"year\": 2008,\n      \"claim\": \"NMR demonstration that melatonin is neither a substrate nor a co-substrate of QR2 resolved a long-standing question about the functional consequence of melatonin binding to the MT3/NQO2 site.\",\n      \"evidence\": \"NMR spectroscopy monitoring QR2 catalytic reaction products in the presence of melatonin\",\n      \"pmids\": [\"18826489\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"If melatonin is not a substrate, the biological purpose of its binding to NQO2 remains unknown\", \"Allosteric effects of melatonin on QR2 not assessed\"]\n    },\n    {\n      \"year\": 2009,\n      \"claim\": \"Discovery of an unusually stable RNA G-quadruplex in the MT3-MMP 5′-UTR that represses translation by >50% identified a novel post-transcriptional regulatory mechanism for this protease.\",\n      \"evidence\": \"CD spectroscopy, RNase T1 footprinting, thermal melting, dual luciferase reporter assay\",\n      \"pmids\": [\"19397366\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"In vivo relevance of G-quadruplex-mediated repression not shown\", \"Trans-acting factors that modulate the G-quadruplex unknown\"]\n    },\n    {\n      \"year\": 2011,\n      \"claim\": \"Demonstrating that MT3-MMP forms membrane complexes with MT1-MMP, reduces MT1-MMP surface expression, and switches invasion preference from collagen to fibrin matrices resolved how two co-expressed MT-MMPs functionally antagonize each other.\",\n      \"evidence\": \"Co-immunoprecipitation, shRNA silencing, overexpression, 3-D collagen and fibrin invasion assays in melanoma cells\",\n      \"pmids\": [\"22164270\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Structural basis of MT3-MMP/MT1-MMP complex unknown\", \"Whether this interaction occurs in non-melanoma contexts not tested\"]\n    },\n    {\n      \"year\": 2012,\n      \"claim\": \"Pharmacological unfolding of the MT3-MMP 5′-UTR G-quadruplex by TmPyP4 relieved translational repression in a structure-dependent manner, validating the G-quadruplex as a druggable translational regulatory element.\",\n      \"evidence\": \"CD, 1D ¹H NMR, native gel electrophoresis, dual luciferase reporter with G-quadruplex mutant control\",\n      \"pmids\": [\"22266651\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Selectivity of TmPyP4 for MT3-MMP G-quadruplex vs. other G-quadruplexes not assessed\", \"Effect on endogenous MT3-MMP protein levels not measured\"]\n    },\n    {\n      \"year\": 2016,\n      \"claim\": \"Quantitative ITC measurements of Pb²⁺ binding to Zn7MT-3 revealed thermodynamically favorable displacement of Zn²⁺ in a tri-phasic process, establishing MT-3 as a high-affinity lead-binding protein with slower metal release kinetics than for zinc.\",\n      \"evidence\": \"Isothermal titration calorimetry, EDTA chelation kinetics, circular dichroism\",\n      \"pmids\": [\"26757944\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"In vivo relevance to lead toxicity or neuroprotection not demonstrated\", \"Whether Pb²⁺ binding alters MT-3 bioactivity not tested\"]\n    },\n    {\n      \"year\": 2017,\n      \"claim\": \"Identification of NgR1 as a physiological MT3-MMP substrate whose ectodomain shedding drives excitatory synaptogenesis established a specific neuronal function for this metalloproteinase beyond ECM remodeling.\",\n      \"evidence\": \"MT3-MMP knockout/knockdown, in vitro and in vivo synapse formation assays, rescue with shed NgR1 ectodomain\",\n      \"pmids\": [\"29196321\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Additional neuronal substrates not surveyed\", \"Whether MT3-MMP regulates inhibitory synaptogenesis unknown\", \"Upstream signals activating MT3-MMP in neurons not identified\"]\n    },\n    {\n      \"year\": 2017,\n      \"claim\": \"MT3-MMP was shown to be expressed in cranial neural crest cells and required for their migration, with laminin and N-cadherin identified as degraded substrates, linking MT3-MMP to EMT during embryonic development.\",\n      \"evidence\": \"Morpholino/siRNA knockdown and rescue with recombinant MMP16 in chick embryos, substrate degradation analysis\",\n      \"pmids\": [\"28621422\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Mammalian in vivo validation not performed\", \"Whether N-cadherin is a direct cleavage substrate or indirect effect unclear\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"The biological purpose of melatonin binding to NQO2 (MT3) remains undefined — no downstream signaling pathway or physiological outcome has been causally attributed to this interaction. For MT-3 (metallothionein-3), no full-length human structure exists, and in vivo neuroprotective functions await genetic validation. For MT3-MMP, the upstream signals that regulate its expression and surface activity in neurons and during development are uncharacterized.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"Biological function of melatonin–NQO2 interaction unknown\", \"Full-length human MT-3 structure not solved\", \"MT3-MMP transcriptional and post-translational regulation in vivo poorly understood\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0008289\", \"supporting_discovery_ids\": [16, 17, 15]},\n      {\"term_id\": \"GO:0016209\", \"supporting_discovery_ids\": [19]},\n      {\"term_id\": \"GO:0140096\", \"supporting_discovery_ids\": [5, 6, 9, 10, 12]},\n      {\"term_id\": \"GO:0016787\", \"supporting_discovery_ids\": [4, 5, 6, 8]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005886\", \"supporting_discovery_ids\": [5, 7, 8]},\n      {\"term_id\": \"GO:0005794\", \"supporting_discovery_ids\": [7]},\n      {\"term_id\": \"GO:0005768\", \"supporting_discovery_ids\": [7]},\n      {\"term_id\": \"GO:0005829\", \"supporting_discovery_ids\": [0, 1]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-1474244\", \"supporting_discovery_ids\": [5, 6, 10]},\n      {\"term_id\": \"R-HSA-1266738\", \"supporting_discovery_ids\": [12]},\n      {\"term_id\": \"R-HSA-112316\", \"supporting_discovery_ids\": [9]}\n    ],\n    \"complexes\": [\n      \"pro-MMP-2/MT3-MMP/TIMP-2 trimolecular complex\",\n      \"MT1-MMP/MT3-MMP membrane complex\"\n    ],\n    \"partners\": [\n      \"MT1-MMP\",\n      \"MMP2\",\n      \"TIMP2\",\n      \"TIMP3\",\n      \"RTN4R\"\n    ],\n    \"other_free_text\": []\n  }\n}\n```\n\n--- ROUND 2 (R2/R3, augmented corpus) ---\n\n```json\n{\n  \"mechanistic_narrative\": \"MT3 (metallothionein-3/GIF) is a brain-enriched, cysteine-rich metalloprotein that coordinates Cu(I) and Zn(II) in distinct metal-thiolate clusters—a Cu4-thiolate cluster preferentially in the N-terminal beta-domain and an M4S11 cluster in the C-terminal alpha-domain—enabling it to function as a dynamic zinc buffer in neurons and to suppress redox-active Cu(II)-amyloid complexes via transmetallation [PMID:10830840, PMID:21320589]. Its cysteine thiolates confer potent hydroxyl radical scavenging activity that exceeds MT-I/II, protecting neurons and non-neural cells from oxidative damage [PMID:12058024, PMID:12383939]. MT3 regulates lysosomal integrity and autophagic flux through zinc dynamics; under oxidative stress, zinc released from MT3 triggers lysosomal membrane permeabilization and cell death, while MT3 absence reduces lysosomal capacity [PMID:20974010]. MT3 is transcriptionally silenced by CpG island hypermethylation in gastric carcinoma and pediatric AML, and its re-expression induces apoptosis and inhibits proliferation in cancer cells [PMID:12538345, PMID:24962166].\",\n  \"teleology\": [\n    {\n      \"year\": 1991,\n      \"claim\": \"Identification of MT3 as a neuron growth-inhibitory factor resolved the molecular identity of a brain-specific metalloprotein that directly suppresses cortical neuronal survival and neurite outgrowth.\",\n      \"evidence\": \"Purification from human brain with amino acid sequencing and in vitro cortical neuron assay\",\n      \"pmids\": [\"1873033\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Mechanism of neurite inhibition unknown\", \"Whether reduced MT3 in AD astrocytes is causative or consequential not resolved\"]\n    },\n    {\n      \"year\": 1992,\n      \"claim\": \"Cloning established MT3 as a distinct metallothionein gene with brain-restricted expression and unique transcriptional non-responsiveness to classical MT inducers (zinc, cadmium, dexamethasone), demarcating it from MT-I/II.\",\n      \"evidence\": \"Molecular cloning, Northern blot, in vivo metal/hormone challenge in multiple species\",\n      \"pmids\": [\"1631128\", \"1464312\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Transcription factor(s) controlling brain-specific expression not identified\", \"Whether non-responsiveness to metals is promoter-intrinsic not tested\"]\n    },\n    {\n      \"year\": 1996,\n      \"claim\": \"MT3 knockout mice revealed an in vivo role in zinc-dependent neuromodulation, showing heightened kainate seizure sensitivity and localizing MT3 to hippocampal zinc-containing neurons rather than glia.\",\n      \"evidence\": \"MT3 knockout mouse, immunohistochemistry, kainate seizure model\",\n      \"pmids\": [\"8751715\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Downstream zinc-dependent targets mediating seizure susceptibility unidentified\", \"Contribution of MT3 to synaptic zinc release not directly measured\"]\n    },\n    {\n      \"year\": 1998,\n      \"claim\": \"Spectroscopic characterization of recombinant MT3 domains defined the metal-thiolate cluster architecture—Cu4S9 preferentially in the beta-domain, M4S11 in the alpha-domain—establishing the structural basis for MT3's distinct metal-handling properties.\",\n      \"evidence\": \"Electronic absorption, CD, MCD, luminescence spectroscopy, 113Cd NMR on isolated alpha-domain and full-length protein\",\n      \"pmids\": [\"9778374\", \"10830840\", \"12072966\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Full-length solution structure not determined at this stage\", \"In vivo metal stoichiometry under physiological conditions uncertain\"]\n    },\n    {\n      \"year\": 2001,\n      \"claim\": \"Domain-dissection experiments showed that MT3's beta-domain delivers zinc to mitochondrial respiratory complexes (inhibiting respiration) while its alpha-domain is the primary hydroxyl radical scavenger, establishing domain-specific functional duality.\",\n      \"evidence\": \"Mitochondrial import/respiration assay with isolated domains; EPR spin-trapping and neuronal/PC12 cytotoxicity assays\",\n      \"pmids\": [\"11226237\", \"11750760\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Physiological relevance of mitochondrial zinc delivery not confirmed in intact neurons\", \"Relative contributions of the two domains to neuroprotection in vivo unknown\"]\n    },\n    {\n      \"year\": 2002,\n      \"claim\": \"Cysteine thiolates were identified as the essential functional groups for MT3's antioxidant activity: NEM alkylation abolished protection against DNA damage and ROS, and ESR spin-trapping demonstrated MT3 scavenges hydroxyl radicals more efficiently than MT-I/II; noncooperative zinc binding and higher metal-transfer potential distinguished MT3 as a dynamic zinc buffer.\",\n      \"evidence\": \"Plasmid DNA damage assay with NEM modification; ESR spin-trapping; mass spectrometry and EDTA competition for metal binding kinetics\",\n      \"pmids\": [\"12383939\", \"12058024\", \"11994011\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Structural basis for noncooperative binding not resolved\", \"Whether dynamic zinc buffering occurs on synaptic timescales not tested\"]\n    },\n    {\n      \"year\": 2003,\n      \"claim\": \"Epigenetic silencing of MT3 by CpG island hypermethylation was established as a mechanism for its loss in cancer, with 5-azacytidine treatment restoring expression in gastric carcinoma cells.\",\n      \"evidence\": \"Bisulfite sequencing, DHPLC methylation analysis, 5-azacytidine demethylation in cell lines and primary tumors\",\n      \"pmids\": [\"12538345\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Whether methylation-mediated silencing is a driver or passenger event in tumorigenesis not determined\", \"Methyl-CpG-binding proteins responsible not identified\"]\n    },\n    {\n      \"year\": 2004,\n      \"claim\": \"MT3 was found to modulate cell death fate: its expression in renal cells shifted Cd2+-induced death from apoptosis to necrosis, revealing that MT3 does not simply protect against metal toxicity but actively redirects the mode of cell death.\",\n      \"evidence\": \"Stable MT3 transfection into HK-2 cells with Cd2+ challenge and apoptosis/necrosis quantification\",\n      \"pmids\": [\"15129022\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Mechanism by which MT3 switches apoptosis to necrosis (e.g., zinc release, mitochondrial effects) not elucidated\", \"Relevance to neuronal cell death not tested\"]\n    },\n    {\n      \"year\": 2010,\n      \"claim\": \"MT3 was shown to regulate lysosomal integrity and autophagic flux through zinc dynamics: MT3-null cells had reduced LAMP-1/2 and lysosomal enzymes, while stress-induced zinc release from MT3 triggered lysosomal membrane permeabilization.\",\n      \"evidence\": \"MT3-null brain cell studies with lysosomal enzyme assays, LAMP protein quantification, and oxidative stress challenge\",\n      \"pmids\": [\"20974010\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Identity of the zinc-sensitive lysosomal target(s) unknown\", \"Whether lysosomal zinc release is the mechanism linking MT3 to necrotic death remains correlative\"]\n    },\n    {\n      \"year\": 2011,\n      \"claim\": \"Zn7-MT3 was shown to suppress α-synuclein-Cu(II) redox toxicity through transmetallation: MT3's thiolates reduce Cu(II) to Cu(I), sequestering it in an oxygen-stable Cu(I)4-thiolate cluster and abolishing α-Syn oligomerization and ROS production.\",\n      \"evidence\": \"Stopped-flow kinetics, UV-vis/CD spectroscopy, mass spectrometry, ROS and aggregation assays with reconstituted α-Syn-Cu(II) complexes\",\n      \"pmids\": [\"21320589\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"In vivo relevance to Parkinson's disease pathology not demonstrated\", \"Whether MT3 similarly detoxifies Cu-Aβ complexes in vivo remains unresolved\"]\n    },\n    {\n      \"year\": 2016,\n      \"claim\": \"Thermodynamic characterization of Pb(II) binding to MT3 revealed entropically driven displacement of zinc, with three distinct binding populations and pH-stable Pb-MT3 complexes, establishing MT3 as a potential lead sequestrant.\",\n      \"evidence\": \"Isothermal titration calorimetry, EDTA chelation kinetics, CD spectroscopy on full-length and isolated domains\",\n      \"pmids\": [\"26757944\", \"30516222\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Physiological relevance of Pb sequestration in neurotoxicity not tested in cellular or animal models\", \"Whether Pb binding disrupts MT3's zinc-buffering or antioxidant functions unknown\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"The in vivo mechanisms linking MT3's zinc-release dynamics to lysosomal regulation, the structural determinants of the apoptosis-to-necrosis switch, and the functional significance of MT3 transmetallation in neurodegenerative disease models remain unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"High\",\n      \"gaps\": [\"No conditional knockout studies targeting MT3 in disease models\", \"No high-resolution full-length structure of mixed Cu/Zn-loaded MT3\", \"Direct in vivo evidence for MT3-mediated Cu-amyloid detoxification lacking\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0016209\", \"supporting_discovery_ids\": [9, 11, 13, 14]},\n      {\"term_id\": \"GO:0140313\", \"supporting_discovery_ids\": [4, 10, 21, 23, 25]},\n      {\"term_id\": \"GO:0008289\", \"supporting_discovery_ids\": [5, 7, 10, 12]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005829\", \"supporting_discovery_ids\": [0, 4]},\n      {\"term_id\": \"GO:0005764\", \"supporting_discovery_ids\": [20]},\n      {\"term_id\": \"GO:0005739\", \"supporting_discovery_ids\": [8]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-8953897\", \"supporting_discovery_ids\": [9, 11, 13, 14, 20]},\n      {\"term_id\": \"R-HSA-5357801\", \"supporting_discovery_ids\": [16, 22]},\n      {\"term_id\": \"R-HSA-9612973\", \"supporting_discovery_ids\": [20]},\n      {\"term_id\": \"R-HSA-382551\", \"supporting_discovery_ids\": [5, 7, 8, 10]}\n    ],\n    \"complexes\": [],\n    \"partners\": [\n      \"SNCA\"\n    ],\n    \"other_free_text\": []\n  }\n}\n```"}