{"gene":"SLC30A1","run_date":"2026-06-10T07:46:33","timeline":{"discoveries":[{"year":2014,"finding":"ZnT-1 functions as a Zn2+/H+ exchanger to extrude zinc from mammalian cells. Active-site mutagenesis of two amino acids in the putative zinc-binding domain abolished Zn2+ efflux and eliminated protection against Zn2+ toxicity. Efflux was sodium-independent, pH-driven, and calcium-sensitive.","method":"Fluorescent imaging (FluoZin-3, Fura-2) in HEK293T cells, active-site mutagenesis, homology modeling based on YiiP crystal structure","journal":"Metallomics","confidence":"High","confidence_rationale":"Tier 1 / Moderate — in vitro functional assay with mutagenesis in mammalian cells, mechanistic transport characterization with multiple orthogonal fluorescent indicators, single lab","pmids":["24951051"],"is_preprint":false},{"year":2021,"finding":"In primary mouse cortical neurons, ZnT1 functions as a Zn2+/Ca2+ exchanger rather than a Zn2+/H+ exchanger. Knockdown via AAV-shZnT1 increased rates of Zn2+ rise and decreased rates of Zn2+ removal. Elimination of extracellular Ca2+ abolished Zn2+ efflux; increased extracellular Ca2+ enhanced efflux. Intracellular Ca2+ rises (measured by GCaMP6) paralleled cytoplasmic Zn2+ removal.","method":"AAV-shRNA knockdown in primary cortical neurons, FluoZin-3 fluorescence imaging, GCaMP6 Ca2+ imaging, ion substitution experiments","journal":"Cell calcium","confidence":"High","confidence_rationale":"Tier 2 / Moderate — clean KD with defined transport phenotype, multiple orthogonal methods (Zn2+ imaging, Ca2+ imaging, ion substitution), single lab","pmids":["34871934"],"is_preprint":false},{"year":2017,"finding":"ZnT-1 is a dual-function protein: its Zn2+/H+ transport activity and its inhibition of the L-type calcium channel (LTCC) are structurally independent functions. Mutations in membrane-spanning helices that abolish zinc transport do not prevent LTCC inhibition. The intracellular C-terminal domain alone (lacking all ion-transfer segments) inhibits LTCC as efficiently as wild-type ZnT-1.","method":"Site-directed mutagenesis, truncation constructs, electrophysiology in Xenopus oocytes and mammalian cells","journal":"Metallomics","confidence":"High","confidence_rationale":"Tier 1 / Moderate — mutagenesis and domain-deletion experiments with functional electrophysiology readout, multiple orthogonal approaches, single lab","pmids":["28091657"],"is_preprint":false},{"year":2004,"finding":"ZnT-1 reduces intracellular zinc by modulating influx rather than accelerating efflux. Co-expression of ZnT-1 with the L-type calcium channel (LTCC) reduced the rate of zinc influx ~3-fold in HEK293 and PC-12 cells. ZnT-1 expression did not alter LTCC protein levels, indicating functional rather than expressional regulation of the channel.","method":"Fluorescent zinc transport measurements in HEK293/PC-12 cells, immunoblot for LTCC expression, overexpression of ZnT-1 with LTCC","journal":"Biochemical and biophysical research communications","confidence":"Medium","confidence_rationale":"Tier 2 / Weak — single lab, single primary method (fluorescence), but two cell lines tested and negative control for LTCC protein levels","pmids":["15451416"],"is_preprint":false},{"year":2006,"finding":"ZnT-1 silencing (siRNA) in cortical neurons caused ~70% reduction in ZnT-1 expression, increased Ca2+ influx via LTCC ~4-fold, increased synaptic release ~30%, and increased Zn2+ and Cd2+ influx rates through LTCC. This established ZnT-1 as a regulator of cation permeation through L-type Ca2+ channels in neurons.","method":"siRNA knockdown, fluorescent Ca2+/Zn2+/Cd2+ influx measurements, FM1-43 synaptic release assay in cortical neurons and granulosa cells","journal":"Journal of molecular medicine","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — siRNA knockdown with multiple ionic and functional readouts, replicated in two cell types, single lab","pmids":["16741752"],"is_preprint":false},{"year":2006,"finding":"ZnT-1 overexpression or siRNA silencing in cultured cardiomyocytes decreased or increased (respectively) barium influx through LTCC. Co-expression in Xenopus oocytes decreased whole-cell barium current. Rapid pacing increased ZnT-1 protein expression and inhibited LTCC; silencing ZnT-1 prevented pacing-induced LTCC inhibition. In vivo atrial pacing of rats increased atrial ZnT-1 expression in parallel with decreased refractory period.","method":"Overexpression and siRNA knockdown in cardiomyocytes, Xenopus oocyte electrophysiology, in vivo rat atrial pacing, Western blot","journal":"Cell calcium","confidence":"High","confidence_rationale":"Tier 2 / Strong — reciprocal gain/loss-of-function, in vitro and in vivo models, oocyte electrophysiology, single lab with multiple orthogonal methods","pmids":["17196651"],"is_preprint":false},{"year":2011,"finding":"ZnT-1 protects cardiomyocytes from ischemia-reperfusion injury through its C-terminal domain-mediated activation of Raf-1 kinase and downstream ERK signaling. A C-terminal truncation abolished ERK activation and cardioprotection, whereas expression of the C-terminal domain alone was sufficient for both. MEK inhibitor PD98059 abolished the protective effect.","method":"Overexpression and knockdown in HL-1 cardiomyocytes, truncation constructs, LDH release and caspase activation assays, phospho-ERK immunoblot, MEK inhibitor","journal":"Journal of molecular medicine","confidence":"High","confidence_rationale":"Tier 2 / Moderate — domain-mapping with truncation constructs, pharmacological inhibition, multiple cell death readouts, single lab with multiple orthogonal methods","pmids":["22193398"],"is_preprint":false},{"year":2012,"finding":"ZnT-1 enhances T-type calcium channel (CaV3.1 and CaV3.2) activity and plasma membrane surface expression through Ras-ERK signaling. Co-expression of non-active Raf-1 blocked ZnT-1-mediated ERK phosphorylation and abolished T-type current augmentation. MEK inhibitor PD-98059 abolished the ZnT-1-induced increase in CaV3.1 surface expression (measured by biotinylation and TIRF microscopy).","method":"Xenopus oocyte electrophysiology, CHO cell overexpression, surface biotinylation, TIRF microscopy, dominant-negative Raf-1, MEK inhibitor PD-98059","journal":"American journal of physiology. Cell physiology","confidence":"High","confidence_rationale":"Tier 2 / Moderate — multiple orthogonal methods (electrophysiology, surface biotinylation, TIRF microscopy), two heterologous expression systems, genetic and pharmacological manipulation, single lab","pmids":["22572848"],"is_preprint":false},{"year":2023,"finding":"ZnT1 binds the auxiliary β-subunit of voltage-gated calcium channels (VGCC) and Raf-1 kinase, mediating crosstalk between LTCC and T-type calcium channels. The VGCC β-subunit inhibits ZnT1-induced augmentation of T-type channel (TTCC) function by reducing ZnT1-induced Ras-ERK activation. This effect is specific to ZnT1, as the β-subunit did not affect endothelin-1-induced TTCC surface expression.","method":"Co-expression in Xenopus oocytes and mammalian cells, electrophysiology, co-immunoprecipitation, Western blot for phospho-ERK, surface expression assays","journal":"Metallomics","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — protein-protein interaction combined with functional electrophysiology, single lab, multiple approaches","pmids":["37193665"],"is_preprint":false},{"year":2020,"finding":"Disruption of the ZnT1-GluN2A association by a cell-permeant peptide strongly reduced NMDAR inhibition by synaptic zinc in mouse dorsal cochlear nucleus synapses. Synaptic zinc inhibition of NMDARs required postsynaptic intracellular zinc, indicating that cytoplasmic zinc is transported by ZnT1 to the extracellular space near the NMDAR. This establishes a postsynaptic transporter mechanism (rather than purely presynaptic release/diffusion) for zinc inhibition of NMDARs.","method":"Cell-permeant peptide disruption of ZnT1-GluN2A interaction, electrophysiology in mouse dorsal cochlear nucleus slices, intracellular zinc manipulation","journal":"Science advances","confidence":"High","confidence_rationale":"Tier 2 / Moderate — specific peptide disruption of protein-protein interaction with electrophysiological readout in native tissue, mechanistic dissection with intracellular zinc requirement test, single lab","pmids":["32937457"],"is_preprint":false},{"year":2022,"finding":"Intracellular zinc drives MTF-1 activity in cortical neurons, increasing ZnT1 expression and the number of GluN2A-ZnT1 interactions, thereby enhancing tonic zinc inhibition of NMDAR-mediated currents. This effect was absent when the ZnT1-GluN2A interaction was disrupted by a cell-permeable peptide, linking zinc-responsive gene expression to NMDAR modulation.","method":"MTF-1 reporter assays in cortical neurons, co-immunoprecipitation for GluN2A-ZnT1 interaction, cell-permeant peptide disruption, electrophysiology","journal":"Neuroscience letters","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — multiple methods linking zinc-sensing, gene regulation, protein interaction, and channel function, single lab","pmids":["36202195"],"is_preprint":false},{"year":2000,"finding":"MTF-1 is essential for both basal and metal-induced (zinc and cadmium) regulation of the ZnT1 gene. In vitro DNA-binding assays showed mouse MTF-1 binds avidly to two metal-response elements in the ZnT1 promoter. MTF-1 knockout mouse embryo fibroblasts showed loss of both basal and inducible ZnT1 expression. In vivo, MTF-1 knockout in mice reduced ZnT1 mRNA ~4-6-fold in visceral yolk sac.","method":"In vitro DNA-binding assay, MTF-1 knockout mouse embryo fibroblasts, transgenic MTF-1 knockout mice, in situ hybridization, mRNA induction assays","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1 / Strong — in vitro DNA binding plus genetic KO validation in cells and in vivo, replicated across multiple model systems","pmids":["10952993"],"is_preprint":false},{"year":2019,"finding":"Under zinc-sufficient conditions, ZNT1 accumulates on the plasma membrane. Under zinc-deficient conditions, plasma membrane ZNT1 is endocytosed and degraded through both proteasomal and lysosomal pathways. ZNT1 is N-glycosylated on Asn299 in the extracellular loop between TM domains V and VI; this modification affects stability (non-glycosylated ZNT1 is more stable) but not zinc efflux function or subcellular localization.","method":"Subcellular fractionation, proteasome/lysosome inhibitors, site-directed mutagenesis of Asn299, immunofluorescence, functional zinc resistance assays in human and vertebrate cells","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 2 / Moderate — multiple orthogonal methods (fractionation, inhibitors, mutagenesis, functional assay), systematic dissection of regulation, single lab","pmids":["31471319"],"is_preprint":false},{"year":2013,"finding":"Cooperative functions of ZnT1, metallothionein (MT), and ZnT4 in the cytoplasm are required for full activation of tissue non-specific alkaline phosphatase (TNAP) in the early secretory pathway (ESP). In ZnT1−/−MT−/−ZnT4−/− cells, TNAP activity was significantly reduced despite increased cytosolic zinc. Activity was restored by re-expression of wild-type but not zinc transport-incompetent mutants of ZnT1, demonstrating that ZnT1's zinc transport activity specifically supports ESP zinc enzyme activation.","method":"Triple gene knockout cells, re-expression with wild-type and transport-deficient mutants, TNAP activity assay, zinc supplementation rescue experiments","journal":"PloS one","confidence":"High","confidence_rationale":"Tier 1 / Moderate — genetic KO combined with mutagenesis rescue, specific functional enzyme activity readout, single lab with multiple orthogonal experiments","pmids":["24204829"],"is_preprint":false},{"year":2024,"finding":"Cryo-EM structure combined with site-specific mutagenesis of human SLC30A1 identified a zinc transport mechanism unique within the SLC30A family, with His43 as a critical residue for zinc selectivity. Intestinal Slc30a1 is localized to the basolateral membrane of intestinal epithelial cells by lineage tracing. Intestinal-specific knockout mice showed impaired survival, establishing that intestinal SLC30A1 is essential for systemic zinc homeostasis.","method":"Cryo-EM structure determination, site-directed mutagenesis of His43, tissue-specific knockout mice (intestinal), lineage tracing for localization","journal":"Advanced science","confidence":"High","confidence_rationale":"Tier 1 / Strong — cryo-EM structure plus mutagenesis plus in vivo KO with survival phenotype, multiple orthogonal methods","pmids":["39422023"],"is_preprint":false},{"year":2021,"finding":"Human ZnT1 and a variant were heterologously expressed in S. cerevisiae and purified. The purified hZnT1 variant displayed Zn2+/H+ antiporter activity in vitro. Small-angle X-ray scattering of the soluble C-terminal domain (CTD) showed it forms a dimer with a V-shaped core in solution. The hZnT1-CTD melting temperature increases at acidic pH.","method":"Heterologous expression in yeast, detergent purification, in vitro Zn2+/H+ antiporter activity assay, SAXS analysis of CTD","journal":"Frontiers in chemistry","confidence":"Medium","confidence_rationale":"Tier 1 / Weak — in vitro transport activity demonstrated and structural characterization by SAXS, but single lab and limited mutagenesis validation","pmids":["33996761"],"is_preprint":false},{"year":2009,"finding":"Drosophila ZnT1 (dZnT1) is essential for dietary zinc absorption and functions at the basolateral membrane of enterocytes. Gut-specific silencing caused lethality under zinc scarcity. Human ZnT1, but not ZnT7 or ZnT4, rescued zinc-acquiring defects from dZnT1 silencing, demonstrating functional conservation and specificity.","method":"RNAi in Drosophila (ubiquitous and gut-specific), overexpression of human ZnT1/ZnT7/ZnT4 rescue, immunofluorescence for basolateral localization, zinc tolerance assays","journal":"FASEB journal","confidence":"High","confidence_rationale":"Tier 2 / Moderate — tissue-specific KD with defined phenotype, human rescue specificity test, localization data, ortholog validated as functionally equivalent to mammalian ZnT1","pmids":["19325039"],"is_preprint":false},{"year":2023,"finding":"Somatic in-frame deletions in SLC30A1 (p.L51_A57del, p.L49_L55del) near the zinc-binding site (His43, Asp47) in TM domain II cause primary aldosteronism by inducing pathological Na+ influx in adrenal cells. The SLC30A1 L51_57del variant in a doxycycline-inducible adrenal cell system caused membrane depolarization, opening of voltage-gated Ca2+ channels, increased cytosolic Ca2+, and stimulation of CYP11B2 expression and aldosterone production.","method":"Next-generation sequencing, doxycycline-inducible expression system in adrenal cells, ion current measurements, cytosolic Ca2+ measurements, CYP11B2 mRNA and aldosterone assays","journal":"Nature genetics","confidence":"High","confidence_rationale":"Tier 2 / Moderate — defined loss-of-function mutations with cellular functional characterization through multiple downstream readouts, single lab with multiple orthogonal methods","pmids":["37709865"],"is_preprint":false},{"year":2008,"finding":"ZnT1 silencing by vector-based shRNA (~40% reduction) in cultured rat cortical neurons decreased Zn2+ efflux compared to control neurons, demonstrating that ZnT1 plays a direct role in Zn2+ efflux. ZnT1-dependent efflux was higher in the first 10 min, suggesting dependence on intracellular free Zn2+ concentration or outward Zn2+ gradient.","method":"Vector-based shRNA knockdown in primary cortical neurons, FluoZin-3 microfluorometry to track intracellular Zn2+, EDTA-mediated extracellular Zn2+ removal","journal":"Neuroscience letters","confidence":"Medium","confidence_rationale":"Tier 3 / Moderate — single KD method but replicated in individual neurons with quantitative kinetics; partial (~40%) knockdown limits interpretation","pmids":["19095042"],"is_preprint":false},{"year":2000,"finding":"PC12 cells stably overexpressing wild-type rat ZnT-1 exhibited enhanced Zn2+ efflux and reduced vulnerability to Zn2+-induced death compared to parental cells. Cells expressing dominant-negative ZnT-1 showed opposite characteristics (reduced efflux, increased vulnerability). Zn2+ entered PC12 cells through L-type Ca2+ channels under depolarizing conditions.","method":"Stable cell line overexpression and dominant-negative expression, Zn2+ efflux assays, cell death assays (necrosis/apoptosis), L-type channel pharmacology","journal":"Brain research","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — stable gain and dominant-negative loss of function with functional efflux and cell death readouts, single lab","pmids":["11119691"],"is_preprint":false},{"year":2004,"finding":"Heterologous expression of ZnT-1 in astrocytes slowed intracellular zinc accumulation and reduced sensitivity to toxic zinc levels, functionally demonstrating that ZnT-1 expression is sufficient to confer zinc protection in glial cells. Zinc pretreatment induced ~4-fold increase in endogenous ZnT-1 expression.","method":"Heterologous ZnT-1 expression in primary astrocytes, fluorescence cell imaging for intracellular zinc, cell viability assays, immunoblot","journal":"Glia","confidence":"Medium","confidence_rationale":"Tier 2 / Weak — overexpression with functional readout in primary cells, single lab, single main method","pmids":["15378655"],"is_preprint":false},{"year":2020,"finding":"In human monocyte-derived macrophages, LPS strongly upregulated SLC30A1 mRNA and protein. Ectopic SLC30A1 expression in THP-1 cells was sufficient to promote zinc-containing vesicle formation and localized to both plasma membrane and intracellular zinc-containing vesicles. SLC30A1-positive compartments subjected all contained bacteria to zinc stress, and SLC30A1 overexpression augmented zinc-mediated killing of intracellular E. coli.","method":"LPS stimulation, ectopic overexpression in THP-1 cells, fluorescent zinc vesicle imaging, E. coli zinc stress reporter, bacterial clearance assays, immunofluorescence for localization","journal":"Journal of leukocyte biology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — ectopic expression with multiple functional readouts (vesicle formation, bacterial zinc stress, killing), localization confirmed, single lab","pmids":["32441444"],"is_preprint":false},{"year":2024,"finding":"Myeloid-specific Slc30a1 conditional knockout mice showed increased susceptibility to attenuated Salmonella infection. Slc30a1-deficient macrophages exhibited defective intracellular killing, reduced NF-κB activation, and reduced nitric oxide production. Intracellular zinc accumulated in knockout macrophages, confirming Slc30a1 is required for zinc export, which in turn enables NO-mediated antibacterial activity.","method":"Lyz2-Cre conditional KO mice, Salmonella infection model, intracellular killing assays, NF-κB activation, NO measurement, intracellular zinc fluorescence","journal":"eLife","confidence":"High","confidence_rationale":"Tier 2 / Moderate — in vivo conditional KO with multiple mechanistic readouts, confirmed zinc accumulation phenotype, single lab with multiple orthogonal methods","pmids":["39475776"],"is_preprint":false},{"year":2023,"finding":"ZNT1 in macrophages regulates endosomal zinc levels to control endocytosis of TLR4 and PD-L1. Myeloid-specific ZNT1 deletion in mice increased chronic inflammation, liver fibrosis, tumor numbers, and size. ZNT1-deficient macrophages showed impaired TLR4 and PD-L1 endocytosis, increasing macrophage-induced inflammation and immunosuppression.","method":"Myeloid-specific ZNT1 KO mice, liver tumor models, endocytosis assays for TLR4 and PD-L1, zinc supplementation experiments, immunofluorescence","journal":"Hepatology","confidence":"High","confidence_rationale":"Tier 2 / Moderate — in vivo myeloid-specific KO with defined mechanistic endpoint (endocytosis of specific receptors), multiple functional readouts, single lab","pmids":["37816045"],"is_preprint":false},{"year":2026,"finding":"ZIP3 (in dorsal cochlear nucleus cartwheel cells) and ZIP1 (in hippocampal CA3 cells) physically interact with ZnT1. Co-expression of ZnT1 with ZIP3 or ZIP1 in SH-SY5Y cells enhanced Zn2+ efflux rates compared to ZnT1 alone, supporting a local Zn2+-cycle model where ZIP-mediated import generates intracellular Zn2+ microdomains near ZnT1 to support its activity.","method":"Co-immunoprecipitation for ZIP3/ZIP1-ZnT1 interaction, Zn2+ efflux assays in SH-SY5Y cells with co-expression, immunofluorescence in dorsal cochlear nucleus and hippocampus","journal":"Cellular and molecular life sciences","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — reciprocal interaction plus functional co-expression assay, single lab, mechanistic model tested in heterologous cells","pmids":["41779239"],"is_preprint":false},{"year":1998,"finding":"Intestinal ZnT-1 protein was localized to the basolateral surface of enterocytes lining the villi of duodenum and jejunum by immunofluorescence. Dietary zinc supplementation elevated intestinal ZnT-1 mRNA and protein, while acute oral zinc dose upregulated mRNA without corresponding protein increase in intestine but increased protein in liver, demonstrating tissue-specific post-transcriptional regulation.","method":"Immunofluorescence for subcellular localization, Western blot, dietary zinc manipulation in rats","journal":"Proceedings of the National Academy of Sciences","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — direct localization by immunofluorescence plus in vivo dietary regulation, multiple tissues, single lab","pmids":["9560190"],"is_preprint":false},{"year":2022,"finding":"Overexpression of cell-surface-localized ZIP4 and ZIP5 increased cellular zinc content and caused increased cell-surface ZNT1 and cytosolic MT expression in the absence of added zinc. Elimination of overexpressed ZIP4/ZIP5 led to decreased ZNT1 expression but not MT expression, revealing differential protein-level regulation. In polarized cells, apically localized ZIP4 facilitated basolateral ZNT1 expression, establishing a coordinated expression mechanism for vectorial zinc transport.","method":"ZIP4/ZIP5 overexpression and depletion in cell lines, polarized cell models, zinc content measurement, Western blot for ZNT1 and MT","journal":"Scientific reports","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — gain and loss-of-function experiments with multiple cell systems, single lab, demonstrates coordinated regulation in polarized cells","pmids":["35513474"],"is_preprint":false},{"year":2021,"finding":"Slc30a1-deficient zebrafish show zinc accumulation in NC cells with increased stemness markers and upregulation of snai2 and jag1b. Knockdown of either snai2 or jag1b rescued pharyngeal arch development in Slc30a1-deficient zebrafish. The double zinc-finger domain of Snai2 was identified as a zinc-responsive element regulating jag1b expression, placing Slc30a1 upstream of a Snai2-Jag1b signaling axis in neural crest differentiation.","method":"Zebrafish Slc30a1a/b morpholino knockdown, SMART-seq transcriptomics, rescue experiments with snai2/jag1b knockdown, reporter assays for zinc-finger domain","journal":"MedComm","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — genetic epistasis (double KD rescue) in zebrafish ortholog, transcriptomic analysis, single lab","pmids":["34977877"],"is_preprint":false},{"year":2019,"finding":"Wild-type ZnT1 overexpression results in low intracellular zinc levels. Eight predicted functionally deleterious missense mutations in ZnT1, identified from cancer genomic databases, were validated as loss-of-function mutations: overexpression of these variants did not reduce intracellular zinc levels, confirming their functional impact.","method":"Novel functional zinc transport assays measuring cytosolic zinc levels, overexpression of WT and mutant ZnT1 in cell lines, bioinformatics analysis of COSMIC/gnomAD databases","journal":"Cell death discovery","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — functional validation of multiple specific mutations with quantitative zinc transport assay, single lab, bioinformatic prediction supported by functional data","pmids":["31728210"],"is_preprint":false},{"year":2016,"finding":"MTF1 knockdown in Caco-2 cells augmented the transcriptome response to zinc for most genes but abolished zinc-responsive regulation of ZnT1 and metallothionein genes specifically, demonstrating that MTF1 directly controls ZnT1 and MT expression to buffer cellular zinc homeostasis.","method":"siRNA-mediated MTF1 knockdown in Caco-2 cells, transcriptome analysis, metallothionein overexpression validation","journal":"Metallomics","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — siRNA KD plus transcriptome readout plus overexpression rescue experiment, single lab","pmids":["26824222"],"is_preprint":false}],"current_model":"SLC30A1/ZnT1 is the principal plasma membrane zinc efflux transporter in mammalian cells, functioning as a Zn2+/H+ exchanger (or Zn2+/Ca2+ exchanger in neurons), localized to the basolateral membrane of enterocytes and the plasma membrane of diverse cell types, transcriptionally induced by zinc/cadmium via MTF-1 binding to metal-response elements in its promoter and post-translationally regulated by zinc-dependent endocytosis/degradation; beyond zinc transport, ZnT1 inhibits L-type calcium channel activity through its intracellular C-terminal domain and activates Raf-1/ERK signaling to enhance T-type calcium channel surface expression—two functions structurally independent of its zinc transport activity—and in synapses it physically associates with GluN2A to form a zinc microdomain that mediates tonic NMDAR inhibition, while in macrophages it controls endosomal zinc levels for TLR4/PD-L1 endocytosis and antimicrobial zinc toxicity."},"narrative":{"mechanistic_narrative":"SLC30A1/ZnT1 is the principal plasma membrane zinc efflux transporter that protects cells from zinc toxicity and, at the organismal level, governs systemic zinc homeostasis through its basolateral localization in enterocytes [PMID:24951051, PMID:39422023, PMID:9560190]. It functions as a Zn2+/H+ exchanger whose efflux activity depends on conserved zinc-binding residues, with His43 critical for zinc selectivity defined by cryo-EM structure; intestinal-specific deletion impairs survival, establishing this transport role as essential in vivo [PMID:24951051, PMID:39422023]. Its soluble C-terminal domain forms a dimer and the antiporter mechanism has been reconstituted from purified protein [PMID:33996761]. ZnT1 expression is controlled at the transcriptional level by zinc/cadmium-activated MTF-1 binding metal-response elements in its promoter, and post-translationally by zinc-dependent endocytosis and proteasomal/lysosomal degradation, coupling its abundance to cellular zinc status [PMID:10952993, PMID:31471319, PMID:26824222]. Beyond ion transport, ZnT1 carries out transport-independent signaling functions through its intracellular C-terminal domain: it inhibits L-type calcium channels and activates Raf-1/ERK signaling to augment T-type calcium channel surface expression, with these activities mapping to the C-terminus rather than the membrane-spanning transport segments [PMID:28091657, PMID:22193398, PMID:22572848]. At synapses, ZnT1 physically associates with the GluN2A NMDAR subunit to mediate tonic zinc inhibition of NMDAR currents [PMID:32937457, PMID:36202195]. In macrophages, ZnT1 controls endosomal and vesicular zinc to drive antimicrobial zinc toxicity, NO-mediated killing, and endocytosis of TLR4 and PD-L1 [PMID:32441444, PMID:39475776, PMID:37816045]. Somatic in-frame deletions near the zinc-binding site cause primary aldosteronism by inducing pathological Na+ influx and downstream Ca2+-driven CYP11B2/aldosterone production [PMID:37709865].","teleology":[{"year":1998,"claim":"Establishing where ZnT1 acts in the body, intestinal ZnT1 was localized to the basolateral enterocyte surface and shown to be regulated by dietary zinc, framing it as a vectorial zinc-export transporter at the absorptive epithelium.","evidence":"Immunofluorescence and Western blot with dietary zinc manipulation in rats","pmids":["9560190"],"confidence":"Medium","gaps":["Transport mechanism not yet defined","No causal genetic test of intestinal requirement"]},{"year":2000,"claim":"To explain how zinc induces its own export machinery, MTF-1 was shown to bind metal-response elements in the ZnT1 promoter and to be required for basal and metal-induced ZnT1 expression, linking zinc sensing to transporter gene regulation.","evidence":"In vitro DNA-binding, MTF-1 knockout MEFs and knockout mice, in situ hybridization","pmids":["10952993"],"confidence":"High","gaps":["Does not address post-transcriptional regulation","Tissue specificity of induction not fully resolved"]},{"year":2000,"claim":"Demonstrating the cytoprotective payoff of zinc export, ZnT1 overexpression enhanced Zn2+ efflux and reduced zinc-induced death while dominant-negative ZnT1 did the opposite, establishing ZnT1 as a determinant of zinc toxicity resistance.","evidence":"Stable overexpression and dominant-negative expression in PC12 cells, efflux and cell death assays","pmids":["11119691"],"confidence":"Medium","gaps":["Transport mechanism (ion coupling) not determined","Endogenous-level evidence lacking"]},{"year":2004,"claim":"Two studies probed how ZnT1 lowers intracellular zinc, one showing it reduces zinc influx through L-type channels rather than only accelerating efflux, and another confirming sufficiency to confer zinc protection in astrocytes, broadening its role to influx regulation across cell types.","evidence":"Fluorescent zinc transport in HEK293/PC-12 cells with LTCC co-expression; heterologous ZnT1 expression in primary astrocytes","pmids":["15451416","15378655"],"confidence":"Medium","gaps":["Single primary method (fluorescence) in each","Molecular basis of channel modulation unresolved"]},{"year":2006,"claim":"Loss- and gain-of-function across neurons and cardiomyocytes established ZnT1 as a physiological regulator of cation permeation through L-type Ca2+ channels, with in vivo atrial pacing linking ZnT1 induction to channel inhibition.","evidence":"siRNA in cortical neurons; overexpression/knockdown in cardiomyocytes, Xenopus oocyte electrophysiology, in vivo rat atrial pacing","pmids":["16741752","17196651"],"confidence":"High","gaps":["Whether channel regulation requires zinc transport not yet separated","Direct ZnT1-channel interaction not mapped"]},{"year":2008,"claim":"Direct loss-of-function in neurons confirmed ZnT1's intrinsic efflux role, as shRNA knockdown decreased Zn2+ efflux with kinetics dependent on the intracellular zinc gradient.","evidence":"Vector-based shRNA knockdown in primary cortical neurons, FluoZin-3 microfluorometry","pmids":["19095042"],"confidence":"Medium","gaps":["Only ~40% knockdown limits interpretation","Ion-coupling mechanism not addressed"]},{"year":2009,"claim":"Cross-species rescue established functional conservation: Drosophila gut ZnT1 is essential for dietary zinc absorption and human ZnT1 (but not ZnT4/ZnT7) rescued the defect, confirming a conserved, specific basolateral export function.","evidence":"RNAi in Drosophila with human ZnT1/ZnT4/ZnT7 rescue, immunofluorescence, zinc tolerance assays","pmids":["19325039"],"confidence":"High","gaps":["Mammalian in vivo intestinal requirement not yet tested","Transport mechanism not addressed"]},{"year":2011,"claim":"The C-terminal domain was shown to be a signaling module: it activates Raf-1/ERK to protect cardiomyocytes from ischemia-reperfusion injury, with the CTD alone sufficient, revealing a function distinct from zinc transport.","evidence":"Truncation constructs in HL-1 cardiomyocytes, phospho-ERK immunoblot, MEK inhibitor, cell death assays","pmids":["22193398"],"confidence":"High","gaps":["Direct Raf-1 binding not shown here","How ERK activation is initiated by the CTD unresolved"]},{"year":2012,"claim":"Extending the signaling role, ZnT1 was shown to augment T-type Ca2+ channel surface expression via Ras-ERK signaling, with dominant-negative Raf-1 and MEK inhibition blocking the effect, defining a transport-independent channel-trafficking function.","evidence":"Xenopus oocyte/CHO electrophysiology, surface biotinylation, TIRF microscopy, dominant-negative Raf-1, MEK inhibitor","pmids":["22572848"],"confidence":"High","gaps":["Physiological context of T-type augmentation untested in vivo","Mechanism of ERK engagement still indirect"]},{"year":2013,"claim":"A triple-knockout rescue experiment showed ZnT1's zinc transport activity specifically supports activation of secretory-pathway zinc enzymes (TNAP), as only transport-competent ZnT1 restored activity, distinguishing its catalytic from signaling roles.","evidence":"ZnT1/MT/ZnT4 triple-KO cells, re-expression of WT vs transport-deficient mutants, TNAP activity assay","pmids":["24204829"],"confidence":"High","gaps":["Mechanism of zinc delivery to the secretory pathway not resolved","Generalizability to other zinc enzymes untested"]},{"year":2016,"claim":"MTF1 was confirmed as the specific transcriptional controller of ZnT1 and metallothionein among the broader zinc transcriptome, sharpening the regulatory logic of zinc buffering.","evidence":"siRNA MTF1 knockdown in Caco-2 cells, transcriptome analysis","pmids":["26824222"],"confidence":"Medium","gaps":["Direct promoter occupancy not re-demonstrated here","Post-transcriptional layer not addressed"]},{"year":2017,"claim":"Domain dissection definitively separated ZnT1's two activities, showing zinc transport-abolishing mutations leave L-type channel inhibition intact and the CTD alone inhibits the channel, establishing dual, structurally independent functions.","evidence":"Site-directed mutagenesis, truncation constructs, electrophysiology in Xenopus oocytes and mammalian cells","pmids":["28091657"],"confidence":"High","gaps":["Direct CTD-channel interaction surface not mapped","Stoichiometry of inhibition unknown"]},{"year":2019,"claim":"Two studies defined post-translational control: zinc-dependent endocytosis/degradation and N-glycosylation tune ZnT1 stability and surface abundance, and cancer-derived missense mutations were validated as loss-of-function, linking sequence to transport.","evidence":"Subcellular fractionation, proteasome/lysosome inhibitors, Asn299 mutagenesis; functional zinc transport assays of COSMIC/gnomAD variants","pmids":["31471319","31728210"],"confidence":"High","gaps":["E3 ligase / trafficking machinery for endocytosis unidentified","Physiological consequences of cancer variants untested in vivo"]},{"year":2020,"claim":"A postsynaptic ZnT1-GluN2A association was shown to mediate tonic zinc inhibition of NMDARs, with peptide disruption abolishing inhibition, revealing a transporter-based synaptic zinc microdomain mechanism.","evidence":"Cell-permeant peptide disruption, electrophysiology in mouse dorsal cochlear nucleus slices, intracellular zinc manipulation","pmids":["32937457"],"confidence":"High","gaps":["Direct binding interface of ZnT1-GluN2A not mapped","Whether transport activity is required not separated from interaction"]},{"year":2020,"claim":"In macrophages, LPS-induced SLC30A1 was shown to drive zinc-containing vesicle formation and intracellular zinc toxicity against bacteria, extending ZnT1's role to innate antimicrobial defense.","evidence":"LPS stimulation and ectopic overexpression in THP-1 cells, zinc vesicle and bacterial zinc-stress reporters, killing assays","pmids":["32441444"],"confidence":"Medium","gaps":["Based on overexpression rather than endogenous loss of function","Vesicle compartment identity not defined"]},{"year":2021,"claim":"Studies in neurons and zebrafish broadened the picture: ZnT1 acts as a Zn2+/Ca2+ exchanger in cortical neurons, and Slc30a1 loss in zebrafish dysregulates a Snai2-Jag1b axis controlling neural crest differentiation, linking zinc export to development.","evidence":"AAV-shRNA knockdown with Zn2+/Ca2+ imaging and ion substitution in neurons; zebrafish morpholino knockdown, SMART-seq, epistasis rescue","pmids":["34871934","34977877"],"confidence":"High","gaps":["Reconciliation of Zn2+/Ca2+ vs Zn2+/H+ coupling across cell types unresolved","Developmental axis tested only in ortholog"]},{"year":2022,"claim":"Coordinate regulation was demonstrated by linking zinc-importing ZIPs to ZnT1: ZIP4/ZIP5 elevate cell-surface ZNT1, and zinc-driven MTF-1 increases GluN2A-ZnT1 interactions to enhance NMDAR inhibition, integrating import, gene expression, and channel modulation.","evidence":"ZIP4/ZIP5 overexpression/depletion in polarized cells; MTF-1 reporter assays, Co-IP, peptide disruption, electrophysiology in neurons","pmids":["35513474","36202195"],"confidence":"Medium","gaps":["Direct physical coupling of ZIPs and ZnT1 not shown in these studies","In vivo relevance of coordinated expression untested"]},{"year":2023,"claim":"Three studies expanded ZnT1's interaction and disease landscape: it binds the VGCC beta-subunit and Raf-1 to coordinate L-type/T-type channel crosstalk, controls endosomal zinc for TLR4/PD-L1 endocytosis in macrophages, and harbors aldosteronism-causing in-frame deletions that induce pathological Na+ influx.","evidence":"Co-IP and electrophysiology in oocytes/mammalian cells; myeloid-specific KO mice with endocytosis assays; NGS and inducible adrenal-cell expression with ion/Ca2+/CYP11B2 readouts","pmids":["37193665","37816045","37709865"],"confidence":"High","gaps":["Structural basis of beta-subunit/Raf-1 binding unmapped","How zinc-binding-site deletions confer Na+ permeability not structurally resolved"]},{"year":2024,"claim":"Structure and in vivo genetics converged: cryo-EM defined a SLC30A-unique transport mechanism with His43 governing zinc selectivity, and intestinal-specific knockout impaired survival, while myeloid knockout confirmed zinc export enables NO-mediated antibacterial killing.","evidence":"Cryo-EM and His43 mutagenesis with intestinal-specific KO mice; Lyz2-Cre conditional KO with Salmonella infection, NF-kB/NO/zinc readouts","pmids":["39422023","39475776"],"confidence":"High","gaps":["Conformational cycle of transport not captured in multiple states","Whether signaling functions are retained in structural mutants untested"]},{"year":2026,"claim":"ZnT1 was shown to physically interact with importers ZIP3 and ZIP1, and co-expression enhanced Zn2+ efflux, supporting a local Zn2+-cycle model in which ZIP-generated microdomains feed ZnT1 export.","evidence":"Co-IP, co-expression efflux assays in SH-SY5Y cells, immunofluorescence in cochlear nucleus and hippocampus","pmids":["41779239"],"confidence":"Medium","gaps":["Direct microdomain measurement not shown","Stoichiometry and interface of ZIP-ZnT1 complex unknown"]},{"year":null,"claim":"How ZnT1's intracellular C-terminal domain mechanistically engages Raf-1 and ion channels, and whether transport, channel regulation, and signaling are co-regulated at the structural level, remain unresolved.","evidence":"","pmids":[],"confidence":"Medium","gaps":["No structure of the CTD bound to Raf-1 or a calcium channel","Stoichiometry and conformational coupling between transport and signaling unknown","In vivo importance of the signaling functions versus the transport function not separated genetically"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0005215","term_label":"transporter activity","supporting_discovery_ids":[0,1,14,15,18,19]},{"term_id":"GO:0140104","term_label":"molecular carrier activity","supporting_discovery_ids":[0,1,13]},{"term_id":"GO:0098772","term_label":"molecular function regulator activity","supporting_discovery_ids":[2,3,5,7]},{"term_id":"GO:0140313","term_label":"molecular sequestering activity","supporting_discovery_ids":[9,10]}],"localization":[{"term_id":"GO:0005886","term_label":"plasma membrane","supporting_discovery_ids":[12,14,16,21,25]},{"term_id":"GO:0031410","term_label":"cytoplasmic vesicle","supporting_discovery_ids":[21,23]},{"term_id":"GO:0005768","term_label":"endosome","supporting_discovery_ids":[23]}],"pathway":[{"term_id":"R-HSA-382551","term_label":"Transport of small molecules","supporting_discovery_ids":[0,14,16]},{"term_id":"R-HSA-168256","term_label":"Immune System","supporting_discovery_ids":[21,22,23]},{"term_id":"R-HSA-162582","term_label":"Signal Transduction","supporting_discovery_ids":[6,7,8]},{"term_id":"R-HSA-1643685","term_label":"Disease","supporting_discovery_ids":[17,28]},{"term_id":"R-HSA-112316","term_label":"Neuronal System","supporting_discovery_ids":[9,10]}],"complexes":[],"partners":["GLUN2A","RAF1","CACNB","ZIP3","ZIP1","ZIP4","MTF1"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"Q9Y6M5","full_name":"Proton-coupled zinc antiporter SLC30A1","aliases":["Solute carrier family 30 member 1","Zinc transporter 1"],"length_aa":507,"mass_kda":55.3,"function":"Zinc ion:proton antiporter that could function at the plasma membrane mediating zinc efflux from cells against its electrochemical gradient protecting them from intracellular zinc accumulation and toxicity (PubMed:31471319). Alternatively, could prevent the transport to the plasma membrane of CACNB2, the L-type calcium channels regulatory subunit, through a yet to be defined mechanism. By modulating the expression of these channels at the plasma membrane, could prevent calcium and zinc influx into cells. By the same mechanism, could also prevent L-type calcium channels-mediated heavy metal influx into cells (By similarity). In some cells, could also function as a zinc ion:proton antiporter mediating zinc entry into the lumen of cytoplasmic vesicles. In macrophages, can increase zinc ions concentration into the lumen of cytoplasmic vesicles containing engulfed bacteria and could help inactivate them (PubMed:32441444). Forms a complex with TMC6/EVER1 and TMC8/EVER2 at the ER membrane of keratynocytes which facilitates zinc uptake into the ER (PubMed:18158319). Down-regulates the activity of transcription factors induced by zinc and cytokines (PubMed:18158319)","subcellular_location":"Cell membrane; Basolateral cell membrane; Cytoplasmic vesicle membrane; Cytoplasm; Endoplasmic reticulum membrane; Golgi apparatus membrane; Nucleus membrane","url":"https://www.uniprot.org/uniprotkb/Q9Y6M5/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/SLC30A1","classification":"Not Classified","n_dependent_lines":8,"n_total_lines":1208,"dependency_fraction":0.006622516556291391},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[{"gene":"CANX","stoichiometry":0.2}],"url":"https://opencell.sf.czbiohub.org/search/SLC30A1","total_profiled":1310},"omim":[{"mim_id":"609617","title":"SOLUTE CARRIER FAMILY 30 (ZINC TRANSPORTER), MEMBER 2; SLC30A2","url":"https://www.omim.org/entry/609617"},{"mim_id":"609521","title":"SOLUTE CARRIER FAMILY 30 (ZINC TRANSPORTER), MEMBER 1; SLC30A1","url":"https://www.omim.org/entry/609521"},{"mim_id":"607819","title":"SOLUTE CARRIER FAMILY 30 (ZINC TRANSPORTER), MEMBER 5; SLC30A5","url":"https://www.omim.org/entry/607819"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Supported","locations":[{"location":"Plasma membrane","reliability":"Supported"},{"location":"Vesicles","reliability":"Additional"}],"tissue_specificity":"Tissue enhanced","tissue_distribution":"Detected in all","driving_tissues":[{"tissue":"liver","ntpm":80.5}],"url":"https://www.proteinatlas.org/search/SLC30A1"},"hgnc":{"alias_symbol":["ZRC1"],"prev_symbol":["ZNT1"]},"alphafold":{"accession":"Q9Y6M5","domains":[{"cath_id":"1.20.1510.10","chopping":"4-137_244-274_312-344","consensus_level":"high","plddt":86.1209,"start":4,"end":344},{"cath_id":"-","chopping":"276-309","consensus_level":"medium","plddt":69.6435,"start":276,"end":309},{"cath_id":"3.30.70.1350","chopping":"346-422","consensus_level":"high","plddt":90.9675,"start":346,"end":422}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q9Y6M5","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q9Y6M5-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q9Y6M5-F1-predicted_aligned_error_v6.png","plddt_mean":67.38},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=SLC30A1","jax_strain_url":"https://www.jax.org/strain/search?query=SLC30A1"},"sequence":{"accession":"Q9Y6M5","fasta_url":"https://rest.uniprot.org/uniprotkb/Q9Y6M5.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q9Y6M5/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q9Y6M5"}},"corpus_meta":[{"pmid":"10952993","id":"PMC_10952993","title":"The transcription factor MTF-1 mediates metal regulation of the mouse ZnT1 gene.","date":"2000","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/10952993","citation_count":325,"is_preprint":false},{"pmid":"9560190","id":"PMC_9560190","title":"Regulation of the zinc transporter ZnT-1 by dietary zinc.","date":"1998","source":"Proceedings of the National Academy of Sciences of the United States of America","url":"https://pubmed.ncbi.nlm.nih.gov/9560190","citation_count":239,"is_preprint":false},{"pmid":"9254680","id":"PMC_9254680","title":"Expression of zinc transporter gene, ZnT-1, is induced after transient forebrain ischemia in the gerbil.","date":"1997","source":"The Journal of neuroscience : the official journal of the Society for Neuroscience","url":"https://pubmed.ncbi.nlm.nih.gov/9254680","citation_count":110,"is_preprint":false},{"pmid":"31471319","id":"PMC_31471319","title":"Zinc transporter 1 (ZNT1) expression on the cell surface is elaborately controlled by cellular zinc levels.","date":"2019","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/31471319","citation_count":93,"is_preprint":false},{"pmid":"17971500","id":"PMC_17971500","title":"Intracellular zinc homeostasis in leukocyte subsets is regulated by different expression of zinc exporters ZnT-1 to ZnT-9.","date":"2007","source":"Journal of leukocyte biology","url":"https://pubmed.ncbi.nlm.nih.gov/17971500","citation_count":93,"is_preprint":false},{"pmid":"11119691","id":"PMC_11119691","title":"L-type Ca(2+) channel-mediated Zn(2+) toxicity and modulation by ZnT-1 in PC12 cells.","date":"2000","source":"Brain research","url":"https://pubmed.ncbi.nlm.nih.gov/11119691","citation_count":88,"is_preprint":false},{"pmid":"15378655","id":"PMC_15378655","title":"ZnT-1 expression in astroglial cells protects against zinc toxicity and slows the accumulation of intracellular zinc.","date":"2004","source":"Glia","url":"https://pubmed.ncbi.nlm.nih.gov/15378655","citation_count":84,"is_preprint":false},{"pmid":"11984815","id":"PMC_11984815","title":"Distribution of the zinc transporter ZnT-1 in comparison with chelatable zinc in the mouse brain.","date":"2002","source":"The Journal of comparative neurology","url":"https://pubmed.ncbi.nlm.nih.gov/11984815","citation_count":81,"is_preprint":false},{"pmid":"26824222","id":"PMC_26824222","title":"Zinc sensing by metal-responsive transcription factor 1 (MTF1) controls metallothionein and ZnT1 expression to buffer the sensitivity of the transcriptome response to zinc.","date":"2016","source":"Metallomics : integrated biometal science","url":"https://pubmed.ncbi.nlm.nih.gov/26824222","citation_count":79,"is_preprint":false},{"pmid":"17101726","id":"PMC_17101726","title":"Immunohistochemical analysis of ZnT1, 4, 5, 6, and 7 in the mouse gastrointestinal tract.","date":"2006","source":"The journal of histochemistry and cytochemistry : official journal of the Histochemistry Society","url":"https://pubmed.ncbi.nlm.nih.gov/17101726","citation_count":76,"is_preprint":false},{"pmid":"19325039","id":"PMC_19325039","title":"Dietary zinc absorption is mediated by ZnT1 in Drosophila melanogaster.","date":"2009","source":"FASEB journal : official publication of the Federation of American Societies for Experimental Biology","url":"https://pubmed.ncbi.nlm.nih.gov/19325039","citation_count":76,"is_preprint":false},{"pmid":"16179263","id":"PMC_16179263","title":"Alterations in zinc transporter protein-1 (ZnT-1) in the brain of subjects with mild cognitive impairment, early, and late-stage Alzheimer's disease.","date":"2005","source":"Neurotoxicity research","url":"https://pubmed.ncbi.nlm.nih.gov/16179263","citation_count":71,"is_preprint":false},{"pmid":"24951051","id":"PMC_24951051","title":"ZnT-1 extrudes zinc from mammalian cells functioning as a Zn(2+)/H(+) exchanger.","date":"2014","source":"Metallomics : integrated biometal science","url":"https://pubmed.ncbi.nlm.nih.gov/24951051","citation_count":68,"is_preprint":false},{"pmid":"18936201","id":"PMC_18936201","title":"Zinc transporters ZnT1 (Slc30a1), Zip8 (Slc39a8), and Zip10 (Slc39a10) in mouse red blood cells are differentially regulated during erythroid development and by dietary zinc deficiency.","date":"2008","source":"The Journal of nutrition","url":"https://pubmed.ncbi.nlm.nih.gov/18936201","citation_count":65,"is_preprint":false},{"pmid":"15867272","id":"PMC_15867272","title":"Zinc deficiency is associated with increased brain zinc import and LIV-1 expression and decreased ZnT-1 expression in neonatal rats.","date":"2005","source":"The Journal of nutrition","url":"https://pubmed.ncbi.nlm.nih.gov/15867272","citation_count":62,"is_preprint":false},{"pmid":"16741752","id":"PMC_16741752","title":"Silencing of ZnT-1 expression enhances heavy metal influx and toxicity.","date":"2006","source":"Journal of molecular medicine (Berlin, Germany)","url":"https://pubmed.ncbi.nlm.nih.gov/16741752","citation_count":60,"is_preprint":false},{"pmid":"15451416","id":"PMC_15451416","title":"A role for ZnT-1 in regulating cellular cation influx.","date":"2004","source":"Biochemical and biophysical research communications","url":"https://pubmed.ncbi.nlm.nih.gov/15451416","citation_count":60,"is_preprint":false},{"pmid":"20392624","id":"PMC_20392624","title":"Increased level of exogenous zinc induces cytotoxicity and up-regulates the expression of the ZnT-1 zinc transporter gene in pancreatic cancer cells.","date":"2010","source":"The Journal of nutritional biochemistry","url":"https://pubmed.ncbi.nlm.nih.gov/20392624","citation_count":58,"is_preprint":false},{"pmid":"32937457","id":"PMC_32937457","title":"Synaptic zinc inhibition of NMDA receptors depends on the association of GluN2A with the zinc transporter ZnT1.","date":"2020","source":"Science 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Active-site mutagenesis of two amino acids in the putative zinc-binding domain abolished Zn2+ efflux and eliminated protection against Zn2+ toxicity. Efflux was sodium-independent, pH-driven, and calcium-sensitive.\",\n      \"method\": \"Fluorescent imaging (FluoZin-3, Fura-2) in HEK293T cells, active-site mutagenesis, homology modeling based on YiiP crystal structure\",\n      \"journal\": \"Metallomics\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — in vitro functional assay with mutagenesis in mammalian cells, mechanistic transport characterization with multiple orthogonal fluorescent indicators, single lab\",\n      \"pmids\": [\"24951051\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"In primary mouse cortical neurons, ZnT1 functions as a Zn2+/Ca2+ exchanger rather than a Zn2+/H+ exchanger. Knockdown via AAV-shZnT1 increased rates of Zn2+ rise and decreased rates of Zn2+ removal. Elimination of extracellular Ca2+ abolished Zn2+ efflux; increased extracellular Ca2+ enhanced efflux. Intracellular Ca2+ rises (measured by GCaMP6) paralleled cytoplasmic Zn2+ removal.\",\n      \"method\": \"AAV-shRNA knockdown in primary cortical neurons, FluoZin-3 fluorescence imaging, GCaMP6 Ca2+ imaging, ion substitution experiments\",\n      \"journal\": \"Cell calcium\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — clean KD with defined transport phenotype, multiple orthogonal methods (Zn2+ imaging, Ca2+ imaging, ion substitution), single lab\",\n      \"pmids\": [\"34871934\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"ZnT-1 is a dual-function protein: its Zn2+/H+ transport activity and its inhibition of the L-type calcium channel (LTCC) are structurally independent functions. Mutations in membrane-spanning helices that abolish zinc transport do not prevent LTCC inhibition. The intracellular C-terminal domain alone (lacking all ion-transfer segments) inhibits LTCC as efficiently as wild-type ZnT-1.\",\n      \"method\": \"Site-directed mutagenesis, truncation constructs, electrophysiology in Xenopus oocytes and mammalian cells\",\n      \"journal\": \"Metallomics\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — mutagenesis and domain-deletion experiments with functional electrophysiology readout, multiple orthogonal approaches, single lab\",\n      \"pmids\": [\"28091657\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2004,\n      \"finding\": \"ZnT-1 reduces intracellular zinc by modulating influx rather than accelerating efflux. Co-expression of ZnT-1 with the L-type calcium channel (LTCC) reduced the rate of zinc influx ~3-fold in HEK293 and PC-12 cells. ZnT-1 expression did not alter LTCC protein levels, indicating functional rather than expressional regulation of the channel.\",\n      \"method\": \"Fluorescent zinc transport measurements in HEK293/PC-12 cells, immunoblot for LTCC expression, overexpression of ZnT-1 with LTCC\",\n      \"journal\": \"Biochemical and biophysical research communications\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Weak — single lab, single primary method (fluorescence), but two cell lines tested and negative control for LTCC protein levels\",\n      \"pmids\": [\"15451416\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2006,\n      \"finding\": \"ZnT-1 silencing (siRNA) in cortical neurons caused ~70% reduction in ZnT-1 expression, increased Ca2+ influx via LTCC ~4-fold, increased synaptic release ~30%, and increased Zn2+ and Cd2+ influx rates through LTCC. This established ZnT-1 as a regulator of cation permeation through L-type Ca2+ channels in neurons.\",\n      \"method\": \"siRNA knockdown, fluorescent Ca2+/Zn2+/Cd2+ influx measurements, FM1-43 synaptic release assay in cortical neurons and granulosa cells\",\n      \"journal\": \"Journal of molecular medicine\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — siRNA knockdown with multiple ionic and functional readouts, replicated in two cell types, single lab\",\n      \"pmids\": [\"16741752\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2006,\n      \"finding\": \"ZnT-1 overexpression or siRNA silencing in cultured cardiomyocytes decreased or increased (respectively) barium influx through LTCC. Co-expression in Xenopus oocytes decreased whole-cell barium current. Rapid pacing increased ZnT-1 protein expression and inhibited LTCC; silencing ZnT-1 prevented pacing-induced LTCC inhibition. In vivo atrial pacing of rats increased atrial ZnT-1 expression in parallel with decreased refractory period.\",\n      \"method\": \"Overexpression and siRNA knockdown in cardiomyocytes, Xenopus oocyte electrophysiology, in vivo rat atrial pacing, Western blot\",\n      \"journal\": \"Cell calcium\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — reciprocal gain/loss-of-function, in vitro and in vivo models, oocyte electrophysiology, single lab with multiple orthogonal methods\",\n      \"pmids\": [\"17196651\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2011,\n      \"finding\": \"ZnT-1 protects cardiomyocytes from ischemia-reperfusion injury through its C-terminal domain-mediated activation of Raf-1 kinase and downstream ERK signaling. A C-terminal truncation abolished ERK activation and cardioprotection, whereas expression of the C-terminal domain alone was sufficient for both. MEK inhibitor PD98059 abolished the protective effect.\",\n      \"method\": \"Overexpression and knockdown in HL-1 cardiomyocytes, truncation constructs, LDH release and caspase activation assays, phospho-ERK immunoblot, MEK inhibitor\",\n      \"journal\": \"Journal of molecular medicine\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — domain-mapping with truncation constructs, pharmacological inhibition, multiple cell death readouts, single lab with multiple orthogonal methods\",\n      \"pmids\": [\"22193398\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"ZnT-1 enhances T-type calcium channel (CaV3.1 and CaV3.2) activity and plasma membrane surface expression through Ras-ERK signaling. Co-expression of non-active Raf-1 blocked ZnT-1-mediated ERK phosphorylation and abolished T-type current augmentation. MEK inhibitor PD-98059 abolished the ZnT-1-induced increase in CaV3.1 surface expression (measured by biotinylation and TIRF microscopy).\",\n      \"method\": \"Xenopus oocyte electrophysiology, CHO cell overexpression, surface biotinylation, TIRF microscopy, dominant-negative Raf-1, MEK inhibitor PD-98059\",\n      \"journal\": \"American journal of physiology. Cell physiology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — multiple orthogonal methods (electrophysiology, surface biotinylation, TIRF microscopy), two heterologous expression systems, genetic and pharmacological manipulation, single lab\",\n      \"pmids\": [\"22572848\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"ZnT1 binds the auxiliary β-subunit of voltage-gated calcium channels (VGCC) and Raf-1 kinase, mediating crosstalk between LTCC and T-type calcium channels. The VGCC β-subunit inhibits ZnT1-induced augmentation of T-type channel (TTCC) function by reducing ZnT1-induced Ras-ERK activation. This effect is specific to ZnT1, as the β-subunit did not affect endothelin-1-induced TTCC surface expression.\",\n      \"method\": \"Co-expression in Xenopus oocytes and mammalian cells, electrophysiology, co-immunoprecipitation, Western blot for phospho-ERK, surface expression assays\",\n      \"journal\": \"Metallomics\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — protein-protein interaction combined with functional electrophysiology, single lab, multiple approaches\",\n      \"pmids\": [\"37193665\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"Disruption of the ZnT1-GluN2A association by a cell-permeant peptide strongly reduced NMDAR inhibition by synaptic zinc in mouse dorsal cochlear nucleus synapses. Synaptic zinc inhibition of NMDARs required postsynaptic intracellular zinc, indicating that cytoplasmic zinc is transported by ZnT1 to the extracellular space near the NMDAR. This establishes a postsynaptic transporter mechanism (rather than purely presynaptic release/diffusion) for zinc inhibition of NMDARs.\",\n      \"method\": \"Cell-permeant peptide disruption of ZnT1-GluN2A interaction, electrophysiology in mouse dorsal cochlear nucleus slices, intracellular zinc manipulation\",\n      \"journal\": \"Science advances\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — specific peptide disruption of protein-protein interaction with electrophysiological readout in native tissue, mechanistic dissection with intracellular zinc requirement test, single lab\",\n      \"pmids\": [\"32937457\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"Intracellular zinc drives MTF-1 activity in cortical neurons, increasing ZnT1 expression and the number of GluN2A-ZnT1 interactions, thereby enhancing tonic zinc inhibition of NMDAR-mediated currents. This effect was absent when the ZnT1-GluN2A interaction was disrupted by a cell-permeable peptide, linking zinc-responsive gene expression to NMDAR modulation.\",\n      \"method\": \"MTF-1 reporter assays in cortical neurons, co-immunoprecipitation for GluN2A-ZnT1 interaction, cell-permeant peptide disruption, electrophysiology\",\n      \"journal\": \"Neuroscience letters\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — multiple methods linking zinc-sensing, gene regulation, protein interaction, and channel function, single lab\",\n      \"pmids\": [\"36202195\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2000,\n      \"finding\": \"MTF-1 is essential for both basal and metal-induced (zinc and cadmium) regulation of the ZnT1 gene. In vitro DNA-binding assays showed mouse MTF-1 binds avidly to two metal-response elements in the ZnT1 promoter. MTF-1 knockout mouse embryo fibroblasts showed loss of both basal and inducible ZnT1 expression. In vivo, MTF-1 knockout in mice reduced ZnT1 mRNA ~4-6-fold in visceral yolk sac.\",\n      \"method\": \"In vitro DNA-binding assay, MTF-1 knockout mouse embryo fibroblasts, transgenic MTF-1 knockout mice, in situ hybridization, mRNA induction assays\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — in vitro DNA binding plus genetic KO validation in cells and in vivo, replicated across multiple model systems\",\n      \"pmids\": [\"10952993\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"Under zinc-sufficient conditions, ZNT1 accumulates on the plasma membrane. Under zinc-deficient conditions, plasma membrane ZNT1 is endocytosed and degraded through both proteasomal and lysosomal pathways. ZNT1 is N-glycosylated on Asn299 in the extracellular loop between TM domains V and VI; this modification affects stability (non-glycosylated ZNT1 is more stable) but not zinc efflux function or subcellular localization.\",\n      \"method\": \"Subcellular fractionation, proteasome/lysosome inhibitors, site-directed mutagenesis of Asn299, immunofluorescence, functional zinc resistance assays in human and vertebrate cells\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — multiple orthogonal methods (fractionation, inhibitors, mutagenesis, functional assay), systematic dissection of regulation, single lab\",\n      \"pmids\": [\"31471319\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"Cooperative functions of ZnT1, metallothionein (MT), and ZnT4 in the cytoplasm are required for full activation of tissue non-specific alkaline phosphatase (TNAP) in the early secretory pathway (ESP). In ZnT1−/−MT−/−ZnT4−/− cells, TNAP activity was significantly reduced despite increased cytosolic zinc. Activity was restored by re-expression of wild-type but not zinc transport-incompetent mutants of ZnT1, demonstrating that ZnT1's zinc transport activity specifically supports ESP zinc enzyme activation.\",\n      \"method\": \"Triple gene knockout cells, re-expression with wild-type and transport-deficient mutants, TNAP activity assay, zinc supplementation rescue experiments\",\n      \"journal\": \"PloS one\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — genetic KO combined with mutagenesis rescue, specific functional enzyme activity readout, single lab with multiple orthogonal experiments\",\n      \"pmids\": [\"24204829\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"Cryo-EM structure combined with site-specific mutagenesis of human SLC30A1 identified a zinc transport mechanism unique within the SLC30A family, with His43 as a critical residue for zinc selectivity. Intestinal Slc30a1 is localized to the basolateral membrane of intestinal epithelial cells by lineage tracing. Intestinal-specific knockout mice showed impaired survival, establishing that intestinal SLC30A1 is essential for systemic zinc homeostasis.\",\n      \"method\": \"Cryo-EM structure determination, site-directed mutagenesis of His43, tissue-specific knockout mice (intestinal), lineage tracing for localization\",\n      \"journal\": \"Advanced science\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — cryo-EM structure plus mutagenesis plus in vivo KO with survival phenotype, multiple orthogonal methods\",\n      \"pmids\": [\"39422023\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"Human ZnT1 and a variant were heterologously expressed in S. cerevisiae and purified. The purified hZnT1 variant displayed Zn2+/H+ antiporter activity in vitro. Small-angle X-ray scattering of the soluble C-terminal domain (CTD) showed it forms a dimer with a V-shaped core in solution. The hZnT1-CTD melting temperature increases at acidic pH.\",\n      \"method\": \"Heterologous expression in yeast, detergent purification, in vitro Zn2+/H+ antiporter activity assay, SAXS analysis of CTD\",\n      \"journal\": \"Frontiers in chemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 1 / Weak — in vitro transport activity demonstrated and structural characterization by SAXS, but single lab and limited mutagenesis validation\",\n      \"pmids\": [\"33996761\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2009,\n      \"finding\": \"Drosophila ZnT1 (dZnT1) is essential for dietary zinc absorption and functions at the basolateral membrane of enterocytes. Gut-specific silencing caused lethality under zinc scarcity. Human ZnT1, but not ZnT7 or ZnT4, rescued zinc-acquiring defects from dZnT1 silencing, demonstrating functional conservation and specificity.\",\n      \"method\": \"RNAi in Drosophila (ubiquitous and gut-specific), overexpression of human ZnT1/ZnT7/ZnT4 rescue, immunofluorescence for basolateral localization, zinc tolerance assays\",\n      \"journal\": \"FASEB journal\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — tissue-specific KD with defined phenotype, human rescue specificity test, localization data, ortholog validated as functionally equivalent to mammalian ZnT1\",\n      \"pmids\": [\"19325039\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"Somatic in-frame deletions in SLC30A1 (p.L51_A57del, p.L49_L55del) near the zinc-binding site (His43, Asp47) in TM domain II cause primary aldosteronism by inducing pathological Na+ influx in adrenal cells. The SLC30A1 L51_57del variant in a doxycycline-inducible adrenal cell system caused membrane depolarization, opening of voltage-gated Ca2+ channels, increased cytosolic Ca2+, and stimulation of CYP11B2 expression and aldosterone production.\",\n      \"method\": \"Next-generation sequencing, doxycycline-inducible expression system in adrenal cells, ion current measurements, cytosolic Ca2+ measurements, CYP11B2 mRNA and aldosterone assays\",\n      \"journal\": \"Nature genetics\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — defined loss-of-function mutations with cellular functional characterization through multiple downstream readouts, single lab with multiple orthogonal methods\",\n      \"pmids\": [\"37709865\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2008,\n      \"finding\": \"ZnT1 silencing by vector-based shRNA (~40% reduction) in cultured rat cortical neurons decreased Zn2+ efflux compared to control neurons, demonstrating that ZnT1 plays a direct role in Zn2+ efflux. ZnT1-dependent efflux was higher in the first 10 min, suggesting dependence on intracellular free Zn2+ concentration or outward Zn2+ gradient.\",\n      \"method\": \"Vector-based shRNA knockdown in primary cortical neurons, FluoZin-3 microfluorometry to track intracellular Zn2+, EDTA-mediated extracellular Zn2+ removal\",\n      \"journal\": \"Neuroscience letters\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 / Moderate — single KD method but replicated in individual neurons with quantitative kinetics; partial (~40%) knockdown limits interpretation\",\n      \"pmids\": [\"19095042\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2000,\n      \"finding\": \"PC12 cells stably overexpressing wild-type rat ZnT-1 exhibited enhanced Zn2+ efflux and reduced vulnerability to Zn2+-induced death compared to parental cells. Cells expressing dominant-negative ZnT-1 showed opposite characteristics (reduced efflux, increased vulnerability). Zn2+ entered PC12 cells through L-type Ca2+ channels under depolarizing conditions.\",\n      \"method\": \"Stable cell line overexpression and dominant-negative expression, Zn2+ efflux assays, cell death assays (necrosis/apoptosis), L-type channel pharmacology\",\n      \"journal\": \"Brain research\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — stable gain and dominant-negative loss of function with functional efflux and cell death readouts, single lab\",\n      \"pmids\": [\"11119691\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2004,\n      \"finding\": \"Heterologous expression of ZnT-1 in astrocytes slowed intracellular zinc accumulation and reduced sensitivity to toxic zinc levels, functionally demonstrating that ZnT-1 expression is sufficient to confer zinc protection in glial cells. Zinc pretreatment induced ~4-fold increase in endogenous ZnT-1 expression.\",\n      \"method\": \"Heterologous ZnT-1 expression in primary astrocytes, fluorescence cell imaging for intracellular zinc, cell viability assays, immunoblot\",\n      \"journal\": \"Glia\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Weak — overexpression with functional readout in primary cells, single lab, single main method\",\n      \"pmids\": [\"15378655\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"In human monocyte-derived macrophages, LPS strongly upregulated SLC30A1 mRNA and protein. Ectopic SLC30A1 expression in THP-1 cells was sufficient to promote zinc-containing vesicle formation and localized to both plasma membrane and intracellular zinc-containing vesicles. SLC30A1-positive compartments subjected all contained bacteria to zinc stress, and SLC30A1 overexpression augmented zinc-mediated killing of intracellular E. coli.\",\n      \"method\": \"LPS stimulation, ectopic overexpression in THP-1 cells, fluorescent zinc vesicle imaging, E. coli zinc stress reporter, bacterial clearance assays, immunofluorescence for localization\",\n      \"journal\": \"Journal of leukocyte biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — ectopic expression with multiple functional readouts (vesicle formation, bacterial zinc stress, killing), localization confirmed, single lab\",\n      \"pmids\": [\"32441444\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"Myeloid-specific Slc30a1 conditional knockout mice showed increased susceptibility to attenuated Salmonella infection. Slc30a1-deficient macrophages exhibited defective intracellular killing, reduced NF-κB activation, and reduced nitric oxide production. Intracellular zinc accumulated in knockout macrophages, confirming Slc30a1 is required for zinc export, which in turn enables NO-mediated antibacterial activity.\",\n      \"method\": \"Lyz2-Cre conditional KO mice, Salmonella infection model, intracellular killing assays, NF-κB activation, NO measurement, intracellular zinc fluorescence\",\n      \"journal\": \"eLife\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — in vivo conditional KO with multiple mechanistic readouts, confirmed zinc accumulation phenotype, single lab with multiple orthogonal methods\",\n      \"pmids\": [\"39475776\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"ZNT1 in macrophages regulates endosomal zinc levels to control endocytosis of TLR4 and PD-L1. Myeloid-specific ZNT1 deletion in mice increased chronic inflammation, liver fibrosis, tumor numbers, and size. ZNT1-deficient macrophages showed impaired TLR4 and PD-L1 endocytosis, increasing macrophage-induced inflammation and immunosuppression.\",\n      \"method\": \"Myeloid-specific ZNT1 KO mice, liver tumor models, endocytosis assays for TLR4 and PD-L1, zinc supplementation experiments, immunofluorescence\",\n      \"journal\": \"Hepatology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — in vivo myeloid-specific KO with defined mechanistic endpoint (endocytosis of specific receptors), multiple functional readouts, single lab\",\n      \"pmids\": [\"37816045\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2026,\n      \"finding\": \"ZIP3 (in dorsal cochlear nucleus cartwheel cells) and ZIP1 (in hippocampal CA3 cells) physically interact with ZnT1. Co-expression of ZnT1 with ZIP3 or ZIP1 in SH-SY5Y cells enhanced Zn2+ efflux rates compared to ZnT1 alone, supporting a local Zn2+-cycle model where ZIP-mediated import generates intracellular Zn2+ microdomains near ZnT1 to support its activity.\",\n      \"method\": \"Co-immunoprecipitation for ZIP3/ZIP1-ZnT1 interaction, Zn2+ efflux assays in SH-SY5Y cells with co-expression, immunofluorescence in dorsal cochlear nucleus and hippocampus\",\n      \"journal\": \"Cellular and molecular life sciences\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — reciprocal interaction plus functional co-expression assay, single lab, mechanistic model tested in heterologous cells\",\n      \"pmids\": [\"41779239\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1998,\n      \"finding\": \"Intestinal ZnT-1 protein was localized to the basolateral surface of enterocytes lining the villi of duodenum and jejunum by immunofluorescence. Dietary zinc supplementation elevated intestinal ZnT-1 mRNA and protein, while acute oral zinc dose upregulated mRNA without corresponding protein increase in intestine but increased protein in liver, demonstrating tissue-specific post-transcriptional regulation.\",\n      \"method\": \"Immunofluorescence for subcellular localization, Western blot, dietary zinc manipulation in rats\",\n      \"journal\": \"Proceedings of the National Academy of Sciences\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — direct localization by immunofluorescence plus in vivo dietary regulation, multiple tissues, single lab\",\n      \"pmids\": [\"9560190\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"Overexpression of cell-surface-localized ZIP4 and ZIP5 increased cellular zinc content and caused increased cell-surface ZNT1 and cytosolic MT expression in the absence of added zinc. Elimination of overexpressed ZIP4/ZIP5 led to decreased ZNT1 expression but not MT expression, revealing differential protein-level regulation. In polarized cells, apically localized ZIP4 facilitated basolateral ZNT1 expression, establishing a coordinated expression mechanism for vectorial zinc transport.\",\n      \"method\": \"ZIP4/ZIP5 overexpression and depletion in cell lines, polarized cell models, zinc content measurement, Western blot for ZNT1 and MT\",\n      \"journal\": \"Scientific reports\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — gain and loss-of-function experiments with multiple cell systems, single lab, demonstrates coordinated regulation in polarized cells\",\n      \"pmids\": [\"35513474\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"Slc30a1-deficient zebrafish show zinc accumulation in NC cells with increased stemness markers and upregulation of snai2 and jag1b. Knockdown of either snai2 or jag1b rescued pharyngeal arch development in Slc30a1-deficient zebrafish. The double zinc-finger domain of Snai2 was identified as a zinc-responsive element regulating jag1b expression, placing Slc30a1 upstream of a Snai2-Jag1b signaling axis in neural crest differentiation.\",\n      \"method\": \"Zebrafish Slc30a1a/b morpholino knockdown, SMART-seq transcriptomics, rescue experiments with snai2/jag1b knockdown, reporter assays for zinc-finger domain\",\n      \"journal\": \"MedComm\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — genetic epistasis (double KD rescue) in zebrafish ortholog, transcriptomic analysis, single lab\",\n      \"pmids\": [\"34977877\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"Wild-type ZnT1 overexpression results in low intracellular zinc levels. Eight predicted functionally deleterious missense mutations in ZnT1, identified from cancer genomic databases, were validated as loss-of-function mutations: overexpression of these variants did not reduce intracellular zinc levels, confirming their functional impact.\",\n      \"method\": \"Novel functional zinc transport assays measuring cytosolic zinc levels, overexpression of WT and mutant ZnT1 in cell lines, bioinformatics analysis of COSMIC/gnomAD databases\",\n      \"journal\": \"Cell death discovery\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — functional validation of multiple specific mutations with quantitative zinc transport assay, single lab, bioinformatic prediction supported by functional data\",\n      \"pmids\": [\"31728210\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"MTF1 knockdown in Caco-2 cells augmented the transcriptome response to zinc for most genes but abolished zinc-responsive regulation of ZnT1 and metallothionein genes specifically, demonstrating that MTF1 directly controls ZnT1 and MT expression to buffer cellular zinc homeostasis.\",\n      \"method\": \"siRNA-mediated MTF1 knockdown in Caco-2 cells, transcriptome analysis, metallothionein overexpression validation\",\n      \"journal\": \"Metallomics\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — siRNA KD plus transcriptome readout plus overexpression rescue experiment, single lab\",\n      \"pmids\": [\"26824222\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"SLC30A1/ZnT1 is the principal plasma membrane zinc efflux transporter in mammalian cells, functioning as a Zn2+/H+ exchanger (or Zn2+/Ca2+ exchanger in neurons), localized to the basolateral membrane of enterocytes and the plasma membrane of diverse cell types, transcriptionally induced by zinc/cadmium via MTF-1 binding to metal-response elements in its promoter and post-translationally regulated by zinc-dependent endocytosis/degradation; beyond zinc transport, ZnT1 inhibits L-type calcium channel activity through its intracellular C-terminal domain and activates Raf-1/ERK signaling to enhance T-type calcium channel surface expression—two functions structurally independent of its zinc transport activity—and in synapses it physically associates with GluN2A to form a zinc microdomain that mediates tonic NMDAR inhibition, while in macrophages it controls endosomal zinc levels for TLR4/PD-L1 endocytosis and antimicrobial zinc toxicity.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"SLC30A1/ZnT1 is the principal plasma membrane zinc efflux transporter that protects cells from zinc toxicity and, at the organismal level, governs systemic zinc homeostasis through its basolateral localization in enterocytes [#0, #14, #25]. It functions as a Zn2+/H+ exchanger whose efflux activity depends on conserved zinc-binding residues, with His43 critical for zinc selectivity defined by cryo-EM structure; intestinal-specific deletion impairs survival, establishing this transport role as essential in vivo [#0, #14]. Its soluble C-terminal domain forms a dimer and the antiporter mechanism has been reconstituted from purified protein [#15]. ZnT1 expression is controlled at the transcriptional level by zinc/cadmium-activated MTF-1 binding metal-response elements in its promoter, and post-translationally by zinc-dependent endocytosis and proteasomal/lysosomal degradation, coupling its abundance to cellular zinc status [#11, #12, #29]. Beyond ion transport, ZnT1 carries out transport-independent signaling functions through its intracellular C-terminal domain: it inhibits L-type calcium channels and activates Raf-1/ERK signaling to augment T-type calcium channel surface expression, with these activities mapping to the C-terminus rather than the membrane-spanning transport segments [#2, #6, #7]. At synapses, ZnT1 physically associates with the GluN2A NMDAR subunit to mediate tonic zinc inhibition of NMDAR currents [#9, #10]. In macrophages, ZnT1 controls endosomal and vesicular zinc to drive antimicrobial zinc toxicity, NO-mediated killing, and endocytosis of TLR4 and PD-L1 [#21, #22, #23]. Somatic in-frame deletions near the zinc-binding site cause primary aldosteronism by inducing pathological Na+ influx and downstream Ca2+-driven CYP11B2/aldosterone production [#17].\",\n  \"teleology\": [\n    {\n      \"year\": 1998,\n      \"claim\": \"Establishing where ZnT1 acts in the body, intestinal ZnT1 was localized to the basolateral enterocyte surface and shown to be regulated by dietary zinc, framing it as a vectorial zinc-export transporter at the absorptive epithelium.\",\n      \"evidence\": \"Immunofluorescence and Western blot with dietary zinc manipulation in rats\",\n      \"pmids\": [\"9560190\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Transport mechanism not yet defined\", \"No causal genetic test of intestinal requirement\"]\n    },\n    {\n      \"year\": 2000,\n      \"claim\": \"To explain how zinc induces its own export machinery, MTF-1 was shown to bind metal-response elements in the ZnT1 promoter and to be required for basal and metal-induced ZnT1 expression, linking zinc sensing to transporter gene regulation.\",\n      \"evidence\": \"In vitro DNA-binding, MTF-1 knockout MEFs and knockout mice, in situ hybridization\",\n      \"pmids\": [\"10952993\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Does not address post-transcriptional regulation\", \"Tissue specificity of induction not fully resolved\"]\n    },\n    {\n      \"year\": 2000,\n      \"claim\": \"Demonstrating the cytoprotective payoff of zinc export, ZnT1 overexpression enhanced Zn2+ efflux and reduced zinc-induced death while dominant-negative ZnT1 did the opposite, establishing ZnT1 as a determinant of zinc toxicity resistance.\",\n      \"evidence\": \"Stable overexpression and dominant-negative expression in PC12 cells, efflux and cell death assays\",\n      \"pmids\": [\"11119691\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Transport mechanism (ion coupling) not determined\", \"Endogenous-level evidence lacking\"]\n    },\n    {\n      \"year\": 2004,\n      \"claim\": \"Two studies probed how ZnT1 lowers intracellular zinc, one showing it reduces zinc influx through L-type channels rather than only accelerating efflux, and another confirming sufficiency to confer zinc protection in astrocytes, broadening its role to influx regulation across cell types.\",\n      \"evidence\": \"Fluorescent zinc transport in HEK293/PC-12 cells with LTCC co-expression; heterologous ZnT1 expression in primary astrocytes\",\n      \"pmids\": [\"15451416\", \"15378655\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Single primary method (fluorescence) in each\", \"Molecular basis of channel modulation unresolved\"]\n    },\n    {\n      \"year\": 2006,\n      \"claim\": \"Loss- and gain-of-function across neurons and cardiomyocytes established ZnT1 as a physiological regulator of cation permeation through L-type Ca2+ channels, with in vivo atrial pacing linking ZnT1 induction to channel inhibition.\",\n      \"evidence\": \"siRNA in cortical neurons; overexpression/knockdown in cardiomyocytes, Xenopus oocyte electrophysiology, in vivo rat atrial pacing\",\n      \"pmids\": [\"16741752\", \"17196651\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Whether channel regulation requires zinc transport not yet separated\", \"Direct ZnT1-channel interaction not mapped\"]\n    },\n    {\n      \"year\": 2008,\n      \"claim\": \"Direct loss-of-function in neurons confirmed ZnT1's intrinsic efflux role, as shRNA knockdown decreased Zn2+ efflux with kinetics dependent on the intracellular zinc gradient.\",\n      \"evidence\": \"Vector-based shRNA knockdown in primary cortical neurons, FluoZin-3 microfluorometry\",\n      \"pmids\": [\"19095042\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Only ~40% knockdown limits interpretation\", \"Ion-coupling mechanism not addressed\"]\n    },\n    {\n      \"year\": 2009,\n      \"claim\": \"Cross-species rescue established functional conservation: Drosophila gut ZnT1 is essential for dietary zinc absorption and human ZnT1 (but not ZnT4/ZnT7) rescued the defect, confirming a conserved, specific basolateral export function.\",\n      \"evidence\": \"RNAi in Drosophila with human ZnT1/ZnT4/ZnT7 rescue, immunofluorescence, zinc tolerance assays\",\n      \"pmids\": [\"19325039\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Mammalian in vivo intestinal requirement not yet tested\", \"Transport mechanism not addressed\"]\n    },\n    {\n      \"year\": 2011,\n      \"claim\": \"The C-terminal domain was shown to be a signaling module: it activates Raf-1/ERK to protect cardiomyocytes from ischemia-reperfusion injury, with the CTD alone sufficient, revealing a function distinct from zinc transport.\",\n      \"evidence\": \"Truncation constructs in HL-1 cardiomyocytes, phospho-ERK immunoblot, MEK inhibitor, cell death assays\",\n      \"pmids\": [\"22193398\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Direct Raf-1 binding not shown here\", \"How ERK activation is initiated by the CTD unresolved\"]\n    },\n    {\n      \"year\": 2012,\n      \"claim\": \"Extending the signaling role, ZnT1 was shown to augment T-type Ca2+ channel surface expression via Ras-ERK signaling, with dominant-negative Raf-1 and MEK inhibition blocking the effect, defining a transport-independent channel-trafficking function.\",\n      \"evidence\": \"Xenopus oocyte/CHO electrophysiology, surface biotinylation, TIRF microscopy, dominant-negative Raf-1, MEK inhibitor\",\n      \"pmids\": [\"22572848\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Physiological context of T-type augmentation untested in vivo\", \"Mechanism of ERK engagement still indirect\"]\n    },\n    {\n      \"year\": 2013,\n      \"claim\": \"A triple-knockout rescue experiment showed ZnT1's zinc transport activity specifically supports activation of secretory-pathway zinc enzymes (TNAP), as only transport-competent ZnT1 restored activity, distinguishing its catalytic from signaling roles.\",\n      \"evidence\": \"ZnT1/MT/ZnT4 triple-KO cells, re-expression of WT vs transport-deficient mutants, TNAP activity assay\",\n      \"pmids\": [\"24204829\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Mechanism of zinc delivery to the secretory pathway not resolved\", \"Generalizability to other zinc enzymes untested\"]\n    },\n    {\n      \"year\": 2016,\n      \"claim\": \"MTF1 was confirmed as the specific transcriptional controller of ZnT1 and metallothionein among the broader zinc transcriptome, sharpening the regulatory logic of zinc buffering.\",\n      \"evidence\": \"siRNA MTF1 knockdown in Caco-2 cells, transcriptome analysis\",\n      \"pmids\": [\"26824222\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct promoter occupancy not re-demonstrated here\", \"Post-transcriptional layer not addressed\"]\n    },\n    {\n      \"year\": 2017,\n      \"claim\": \"Domain dissection definitively separated ZnT1's two activities, showing zinc transport-abolishing mutations leave L-type channel inhibition intact and the CTD alone inhibits the channel, establishing dual, structurally independent functions.\",\n      \"evidence\": \"Site-directed mutagenesis, truncation constructs, electrophysiology in Xenopus oocytes and mammalian cells\",\n      \"pmids\": [\"28091657\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Direct CTD-channel interaction surface not mapped\", \"Stoichiometry of inhibition unknown\"]\n    },\n    {\n      \"year\": 2019,\n      \"claim\": \"Two studies defined post-translational control: zinc-dependent endocytosis/degradation and N-glycosylation tune ZnT1 stability and surface abundance, and cancer-derived missense mutations were validated as loss-of-function, linking sequence to transport.\",\n      \"evidence\": \"Subcellular fractionation, proteasome/lysosome inhibitors, Asn299 mutagenesis; functional zinc transport assays of COSMIC/gnomAD variants\",\n      \"pmids\": [\"31471319\", \"31728210\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"E3 ligase / trafficking machinery for endocytosis unidentified\", \"Physiological consequences of cancer variants untested in vivo\"]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"A postsynaptic ZnT1-GluN2A association was shown to mediate tonic zinc inhibition of NMDARs, with peptide disruption abolishing inhibition, revealing a transporter-based synaptic zinc microdomain mechanism.\",\n      \"evidence\": \"Cell-permeant peptide disruption, electrophysiology in mouse dorsal cochlear nucleus slices, intracellular zinc manipulation\",\n      \"pmids\": [\"32937457\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Direct binding interface of ZnT1-GluN2A not mapped\", \"Whether transport activity is required not separated from interaction\"]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"In macrophages, LPS-induced SLC30A1 was shown to drive zinc-containing vesicle formation and intracellular zinc toxicity against bacteria, extending ZnT1's role to innate antimicrobial defense.\",\n      \"evidence\": \"LPS stimulation and ectopic overexpression in THP-1 cells, zinc vesicle and bacterial zinc-stress reporters, killing assays\",\n      \"pmids\": [\"32441444\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Based on overexpression rather than endogenous loss of function\", \"Vesicle compartment identity not defined\"]\n    },\n    {\n      \"year\": 2021,\n      \"claim\": \"Studies in neurons and zebrafish broadened the picture: ZnT1 acts as a Zn2+/Ca2+ exchanger in cortical neurons, and Slc30a1 loss in zebrafish dysregulates a Snai2-Jag1b axis controlling neural crest differentiation, linking zinc export to development.\",\n      \"evidence\": \"AAV-shRNA knockdown with Zn2+/Ca2+ imaging and ion substitution in neurons; zebrafish morpholino knockdown, SMART-seq, epistasis rescue\",\n      \"pmids\": [\"34871934\", \"34977877\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Reconciliation of Zn2+/Ca2+ vs Zn2+/H+ coupling across cell types unresolved\", \"Developmental axis tested only in ortholog\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Coordinate regulation was demonstrated by linking zinc-importing ZIPs to ZnT1: ZIP4/ZIP5 elevate cell-surface ZNT1, and zinc-driven MTF-1 increases GluN2A-ZnT1 interactions to enhance NMDAR inhibition, integrating import, gene expression, and channel modulation.\",\n      \"evidence\": \"ZIP4/ZIP5 overexpression/depletion in polarized cells; MTF-1 reporter assays, Co-IP, peptide disruption, electrophysiology in neurons\",\n      \"pmids\": [\"35513474\", \"36202195\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct physical coupling of ZIPs and ZnT1 not shown in these studies\", \"In vivo relevance of coordinated expression untested\"]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"Three studies expanded ZnT1's interaction and disease landscape: it binds the VGCC beta-subunit and Raf-1 to coordinate L-type/T-type channel crosstalk, controls endosomal zinc for TLR4/PD-L1 endocytosis in macrophages, and harbors aldosteronism-causing in-frame deletions that induce pathological Na+ influx.\",\n      \"evidence\": \"Co-IP and electrophysiology in oocytes/mammalian cells; myeloid-specific KO mice with endocytosis assays; NGS and inducible adrenal-cell expression with ion/Ca2+/CYP11B2 readouts\",\n      \"pmids\": [\"37193665\", \"37816045\", \"37709865\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Structural basis of beta-subunit/Raf-1 binding unmapped\", \"How zinc-binding-site deletions confer Na+ permeability not structurally resolved\"]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Structure and in vivo genetics converged: cryo-EM defined a SLC30A-unique transport mechanism with His43 governing zinc selectivity, and intestinal-specific knockout impaired survival, while myeloid knockout confirmed zinc export enables NO-mediated antibacterial killing.\",\n      \"evidence\": \"Cryo-EM and His43 mutagenesis with intestinal-specific KO mice; Lyz2-Cre conditional KO with Salmonella infection, NF-kB/NO/zinc readouts\",\n      \"pmids\": [\"39422023\", \"39475776\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Conformational cycle of transport not captured in multiple states\", \"Whether signaling functions are retained in structural mutants untested\"]\n    },\n    {\n      \"year\": 2026,\n      \"claim\": \"ZnT1 was shown to physically interact with importers ZIP3 and ZIP1, and co-expression enhanced Zn2+ efflux, supporting a local Zn2+-cycle model in which ZIP-generated microdomains feed ZnT1 export.\",\n      \"evidence\": \"Co-IP, co-expression efflux assays in SH-SY5Y cells, immunofluorescence in cochlear nucleus and hippocampus\",\n      \"pmids\": [\"41779239\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct microdomain measurement not shown\", \"Stoichiometry and interface of ZIP-ZnT1 complex unknown\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How ZnT1's intracellular C-terminal domain mechanistically engages Raf-1 and ion channels, and whether transport, channel regulation, and signaling are co-regulated at the structural level, remain unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No structure of the CTD bound to Raf-1 or a calcium channel\", \"Stoichiometry and conformational coupling between transport and signaling unknown\", \"In vivo importance of the signaling functions versus the transport function not separated genetically\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0005215\", \"supporting_discovery_ids\": [0, 1, 14, 15, 18, 19]},\n      {\"term_id\": \"GO:0140104\", \"supporting_discovery_ids\": [0, 1, 13]},\n      {\"term_id\": \"GO:0098772\", \"supporting_discovery_ids\": [2, 3, 5, 7]},\n      {\"term_id\": \"GO:0140313\", \"supporting_discovery_ids\": [9, 10]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005886\", \"supporting_discovery_ids\": [12, 14, 16, 21, 25]},\n      {\"term_id\": \"GO:0031410\", \"supporting_discovery_ids\": [21, 23]},\n      {\"term_id\": \"GO:0005768\", \"supporting_discovery_ids\": [23]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-382551\", \"supporting_discovery_ids\": [0, 14, 16]},\n      {\"term_id\": \"R-HSA-168256\", \"supporting_discovery_ids\": [21, 22, 23]},\n      {\"term_id\": \"R-HSA-162582\", \"supporting_discovery_ids\": [6, 7, 8]},\n      {\"term_id\": \"R-HSA-1643685\", \"supporting_discovery_ids\": [17, 28]},\n      {\"term_id\": \"R-HSA-112316\", \"supporting_discovery_ids\": [9, 10]}\n    ],\n    \"complexes\": [],\n    \"partners\": [\"GluN2A\", \"RAF1\", \"CACNB\", \"ZIP3\", \"ZIP1\", \"ZIP4\", \"MTF1\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":7,"faith_total":8,"faith_pct":87.5}}