{"gene":"MCOLN3","run_date":"2026-06-10T02:59:50","timeline":{"discoveries":[{"year":2002,"finding":"MCOLN3/TRPML3 encodes a putative six-transmembrane-domain cation channel protein; the Va allele carries an Ala419Pro substitution in the fifth transmembrane domain causing the varitint-waddler phenotype, while the Va(J) allele has an additional Ile362Thr substitution that partially rescues it. TRPML3 localizes to cytoplasmic compartments of hair cells and plasma membrane of stereocilia, with hair cell defects apparent by embryonic day 17.5.","method":"Positional cloning, sequence analysis, immunolocalization in hair cells","journal":"Proceedings of the National Academy of Sciences of the United States of America","confidence":"High","confidence_rationale":"Tier 2 / Strong — positional cloning with direct mutation identification replicated across multiple subsequent studies; localization confirmed by immunofluorescence","pmids":["12403827"],"is_preprint":false},{"year":2007,"finding":"The Va mutation A419P in TRPML3 generates a constitutively active cation channel (gain-of-function) by a helix-breaking proline substitution in TM5. Proline substitution scan showed the inner third of TM5 is highly susceptible to proline-based kinks causing constitutive activity; the constitutively active channel was detected as a distinct inwardly rectifying current in native varitint-waddler hair cells.","method":"Patch-clamp electrophysiology in heterologous expression and native hair cells; proline substitution scan of TM5","journal":"Proceedings of the National Academy of Sciences of the United States of America","confidence":"High","confidence_rationale":"Tier 1 / Strong — in vitro electrophysiology plus mutagenesis; replicated in native cells and by multiple independent labs","pmids":["18048323"],"is_preprint":false},{"year":2007,"finding":"Wild-type TRPML3 is a strongly inward rectifying cation channel regulated by extracytosolic Na+: pre-incubation in Na+-free medium activates the channel, which then slowly inactivates upon Na+ re-addition. The A419P mutation locks the channel in an open, unregulated state (gain-of-function), affects channel glycosylation, and causes massive cell death. The A419G mutation similarly destabilizes TM5 alpha-helix and produces gain-of-function. I362T results in an inactive channel but does not fully suppress A419P in the double mutant.","method":"Whole-cell patch-clamp electrophysiology, site-directed mutagenesis, cell viability assays in heterologous expression system","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1 / Strong — in vitro electrophysiology with systematic mutagenesis, replicated by multiple labs","pmids":["17962195"],"is_preprint":false},{"year":2007,"finding":"Wild-type TRPML3 forms channels with conductance of 50–70 pS, opens at very positive potentials (outward rectification). The A419P mutant generates an additional constitutive inwardly rectifying current that depolarizes cells. Cells expressing TRPML3(A419P) or TRPML3(I362T+A419P) die and are extruded from the epithelium, resembling degeneration of Va hair cells.","method":"Single-channel and whole-cell patch-clamp in LLC-PK1-CL4 epithelial cells; immunolocalization","journal":"Proceedings of the National Academy of Sciences of the United States of America","confidence":"High","confidence_rationale":"Tier 1 / Strong — single-channel electrophysiology with mutagenesis; replicated across labs","pmids":["18162548"],"is_preprint":false},{"year":2008,"finding":"TRPML3 is a Ca2+-permeable channel uniquely regulated by extracytosolic (luminal) H+ via three histidines (H252, H273, H283) in the large extracytosolic loop between TM1 and TM2. H283A mutation locks the channel open (mimics A419P), while H283R inactivates it. The A419P mutation abolishes H+ regulation, suggesting that the extracytosolic loop communicates with TM5 orientation to control pore opening.","method":"Whole-cell patch-clamp electrophysiology, site-directed mutagenesis, pH manipulation","journal":"The EMBO journal","confidence":"High","confidence_rationale":"Tier 1 / Strong — in vitro electrophysiology with systematic mutagenesis of multiple residues identifying specific regulatory histidines","pmids":["18369318"],"is_preprint":false},{"year":2006,"finding":"TRPML proteins form homo- and heteromultimers. TRPML1 and TRPML2 homomultimers are lysosomal, whereas TRPML3 homomultimers localize to the endoplasmic reticulum. However, TRPML3 is redirected to lysosomes when coexpressed with TRPML1 or TRPML2, demonstrating a hierarchy in which TRPML1 and TRPML2 dictate TRPML3 lysosomal localization but not vice versa.","method":"Co-immunoprecipitation, subcellular fractionation, confocal microscopy with dominant-negative and lysosomal-targeting mutants","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 2 / Strong — reciprocal co-IP plus multiple localization experiments with functional mutants; replicated in subsequent work","pmids":["16606612"],"is_preprint":false},{"year":2008,"finding":"TRPML3 mutations (I362T/A419P) cause reduced mechano-electrical transducer (MET) currents in cochlear hair cells, reduced FM1-43 and gentamicin uptake, and loss of TRPML3 localization at the base of stereocilia near ankle links. The study argues TRPML3 plays a critical role at the ankle-link region during hair-bundle growth and that impaired MET is the main cause of hearing loss in Va(J) heterozygotes, rather than constitutive channel activity.","method":"Electrophysiological recordings of MET currents, FM1-43 and [3H]gentamicin uptake assays, immunohistochemistry with TRPML3-specific antibody","journal":"The Journal of physiology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — direct electrophysiology in native hair cells with antibody localization; single lab, multiple methods","pmids":["18801844"],"is_preprint":false},{"year":2009,"finding":"TRPML3 is a prominent regulator of endocytosis, membrane trafficking, and autophagy. Overexpression of TRPML3 reduces constitutive and regulated endocytosis and increases autophagy. Knockdown of TRPML3 by siRNA or expression of a channel-dead dominant-negative TRPML3(D458K) reduces both endocytosis and autophagy. Upon autophagy induction, TRPML3 is dynamically recruited to autophagosomes, suggesting it controls Ca2+ in the vicinity of cellular organelles needed for these events.","method":"Gradient fractionation, confocal localization, siRNA knockdown, dominant-negative expression, endocytosis and autophagy assays","journal":"Traffic (Copenhagen, Denmark)","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — multiple orthogonal methods (KD, DN, localization, functional assays) in a single lab","pmids":["19522758"],"is_preprint":false},{"year":2009,"finding":"PMCA2 (plasma membrane calcium ATPase 2) significantly reduces [Ca2+]i increase and apoptosis in HEK293 cells expressing constitutively active TRPML3(A419P). Genetic epistasis in mice: combining heterozygous Va (TRPML3 A419P) with heterozygous deaf-waddler (PMCA2 G283S) alleles causes severe hair bundle defects and increased hair cell loss compared to single mutants, establishing PMCA2 as a functional suppressor of TRPML3(A419P)-induced Ca2+ overload.","method":"Ca2+ imaging, apoptosis assays in HEK293 cells; double-mutant mouse genetics with auditory brainstem responses","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 2 / Strong — genetic epistasis in vivo combined with in vitro Ca2+ measurements and functional cell death assay","pmids":["19299509"],"is_preprint":false},{"year":2010,"finding":"The TRPML3 pore is dynamic during Ca2+ conduction: it changes conductance and permeability, apparently by trapping Ca2+ within the pore, and can be restored by strong depolarization or Na+ conduction. The A419P mutation results in an expanded channel pore with altered permeability that limits Ca2+-mediated pore modulation; this effect is specific to A419P and is not reproduced by other gain-of-function mutations (A419G, H283A, or other TM5 prolines).","method":"Whole-cell and single-channel patch-clamp electrophysiology, site-directed mutagenesis","journal":"The Journal of biological chemistry","confidence":"Medium","confidence_rationale":"Tier 1 / Moderate — in vitro electrophysiology with mutagenesis, single lab","pmids":["20378547"],"is_preprint":false},{"year":2010,"finding":"Genetic inactivation (conditional knockout) of Trpml3 in mice does not lead to hearing loss, vestibular impairment, or circling behavior, establishing that TRPML3 loss-of-function alone is not sufficient to cause auditory/vestibular phenotypes under normal conditions.","method":"Conditional knockout mouse, auditory brainstem response testing, behavioral observation","journal":"PloS one","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — clean genetic knockout with defined phenotypic readout; single lab but rigorous negative result","pmids":["21179200"],"is_preprint":false},{"year":2010,"finding":"TRPML3 can be activated by low extracytosolic sodium and by diverse small molecules identified in a high-throughput screen. Agonists synergize with low extracytosolic [Na+], revealing distinct cooperative activation mechanisms. Testing on native sensory hair cells and melanocytes shows absence of activator-responsive channels, suggesting TRPML3 is absent from the plasma membrane in these native cells or is part of nonresponsive heteromeric channels.","method":"High-throughput fluorescence-based screen, electrophysiology, cheminformatics, native cell testing","journal":"Chemistry & biology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — large screen plus electrophysiological validation; single lab, multiple methods","pmids":["20189104"],"is_preprint":false},{"year":2012,"finding":"Glu-361 in the second extracellular loop of TRPML3 is critical for sodium-mediated block; mutating this negatively charged residue significantly reduces the sodium inhibition of TRPML3. TRPML2 is also activated by lowering extracellular sodium concentration and by a subset of TRPML3 agonists, suggesting similar gating mechanisms for both channels.","method":"Site-directed mutagenesis, whole-cell patch-clamp electrophysiology, pharmacological screening","journal":"The Journal of biological chemistry","confidence":"Medium","confidence_rationale":"Tier 1 / Moderate — mutagenesis plus electrophysiology; single lab identifying a specific regulatory residue","pmids":["22753890"],"is_preprint":false},{"year":2013,"finding":"TRPML3 and TRPV5 physically associate to form a novel heteromeric ion channel with pharmacological properties similar to TRPML3 but distinct single-channel features from either homomeric channel. The heteromer requires functional TRPML3 and functional TRPV5, and occurs in potentially distinct stoichiometric configurations.","method":"Co-immunoprecipitation, single-channel patch-clamp electrophysiology, pharmacology","journal":"PloS one","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — co-IP plus single-channel electrophysiology demonstrating novel conductance; single lab","pmids":["23469151"],"is_preprint":false},{"year":2017,"finding":"Cryo-EM structure of full-length marmoset TRPML3 at 2.9 Å resolution reveals: (1) a unique architecture where the voltage sensor-like domain is linked to the pore via a cytosolic 'mucolipin domain'; (2) the mucolipin domain is responsible for PtdIns(3,5)P2 binding and channel activation; (3) it acts as a 'gating pulley' for lipid-dependent channel gating. Conserved basic residues at the N-terminus mediate PtdIns(3,5)P2 activation and PtdIns(4,5)P2 inhibition.","method":"Cryo-EM structure determination, functional electrophysiology with mutagenesis of basic residues","journal":"Nature","confidence":"High","confidence_rationale":"Tier 1 / Strong — high-resolution cryo-EM structure plus functional validation by mutagenesis; published in Nature","pmids":["29019979"],"is_preprint":false},{"year":2017,"finding":"Cryo-EM structures of human TRPML3 in closed, agonist-activated (ML-SA1 bound), and low-pH-inhibited states. The agonist ML-SA1 lodges between S5 and S6 and opens the S6 gate. A polycystin-mucolipin domain (PMD) forms a luminal cap; S1 extends into this cap as a 'gating rod' connected to a luminal pore loop that undergoes dramatic conformational changes at low pH. S2 extends intracellularly forming a 'gating knob'. Low pH induces inhibition by changing S1 and S2 conformations. PIP2 regulation also acts through S1 and S2 conformational changes.","method":"Cryo-EM structure determination at 3.62–4.65 Å, electrophysiology, agonist binding studies","journal":"Nature structural & molecular biology","confidence":"High","confidence_rationale":"Tier 1 / Strong — three cryo-EM structures capturing distinct functional states combined with electrophysiology; complements marmoset structure in same year","pmids":["29106414"],"is_preprint":false},{"year":2018,"finding":"MCOLN3/TRPML3 undergoes palmitoylation at its C-terminal region. Palmitoylation is required for dynamic trafficking of MCOLN3 to autophagic structures and for MCOLN3's function in autophagosome formation, but not for channel properties or localization/function of intracellular MCOLN3. Nutrient starvation activates MCOLN3 and increases its palmitoylation level; disruption of palmitoylation abolishes starvation-induced channel activation without affecting intrinsic channel activity.","method":"Mass spectrometry for palmitoylation site identification, 2-BP inhibitor studies, hydroxylamine treatment, Ca2+ imaging, autophagy flux assays, shRNA knockdown","journal":"Autophagy","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — MS identification of modification site combined with functional palmitoylation inhibition and trafficking assays; single lab, multiple orthogonal methods","pmids":["30215288"],"is_preprint":false},{"year":2022,"finding":"TRPML3 localizes in phagophores and is a downstream effector of phosphatidylinositol-3-phosphate (PI3P). PI3P directly activates TRPML3 current and Ca2+ release from the phagophore to promote autophagosome biogenesis. TRPML3 physically interacts with PI3P; disruption of this interaction abolishes both PI3P-dependent activation and the increase in autophagy. Inhibition of TRPML3 suppresses autophagy even in the presence of excess PI3P.","method":"TRPML3-GCaMP6 targeted reporter Ca2+ imaging, patch-clamp electrophysiology, lipid-binding assays, autophagy flux assays, KO and activation studies","journal":"Proceedings of the National Academy of Sciences of the United States of America","confidence":"High","confidence_rationale":"Tier 2 / Strong — multiple orthogonal methods (Ca2+ reporter, electrophysiology, lipid binding, genetic loss/gain of function) establishing PI3P as direct TRPML3 activator","pmids":["36252030"],"is_preprint":false},{"year":2022,"finding":"FGL2 (fibrinogen-like protein 2) directly interacts with mucolipin 3 (MCOLN3/TRPML3) in neutrophils, regulating calcium influx and initiating autophagy that leads to neutrophil extracellular trap (NET) formation. This FGL2-MCOLN3-autophagy axis drives NET-mediated liver injury in fulminant viral hepatitis.","method":"Co-immunoprecipitation (direct interaction), adoptive transfer experiments, siRNA/shRNA knockdown, calcium flux assays","journal":"Cellular and molecular gastroenterology and hepatology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — co-IP establishing direct interaction plus functional assays in cells and in vivo model; single lab","pmids":["35926777"],"is_preprint":false},{"year":2025,"finding":"Somatic gain-of-function mutations in MCOLN3 (p.Y391D, p.F415I, p.N411_V412delinsI), located near the ion pore and selectivity filter, cause membrane depolarization and calcium influx in adrenocortical HAC15 cells, triggering increased CYP11B2 (aldosterone synthase) expression and aldosterone production, establishing MCOLN3 as a driver gene for primary aldosteronism.","method":"Next-generation sequencing of APAs, electrophysiology, fura-2 calcium measurements, gene expression assays, steroid quantification in transfected adrenocortical cells","journal":"Hypertension (Dallas, Tex. : 1979)","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — electrophysiology plus Ca2+ measurements plus downstream gene expression and steroid output in transfected cells; single lab, multiple orthogonal methods","pmids":["40772318"],"is_preprint":false},{"year":2025,"finding":"MCOLN1/TRPML1 and MCOLN3/TRPML3 form a heteromeric channel that acts downstream of PtdIns4P to release Ca2+ from autophagosomes for autophagosome-lysosome fusion. The Ca2+ signal is decoded by the Ca2+ sensor SYT5 (synaptotagmin 5), which binds both Ca2+ and PtdIns4P to form a fusion complex. Disruption of the MCOLN1-MCOLN3 heteromer or the MCOLN3-SYT5 interaction inhibits autophagosome-lysosome fusion.","method":"Co-immunoprecipitation, Ca2+ imaging, autophagy flux assays, KO cells, dominant-negative constructs, lipid-binding assays","journal":"Autophagy","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — co-IP, Ca2+ imaging, KO and DN studies establishing heteromeric complex and downstream effector; single lab, multiple orthogonal methods","pmids":["40413756"],"is_preprint":false},{"year":2025,"finding":"TRPML3 specifically interacts with the mammalian ATG8 homolog GATE16 (but not LC3B) through single amino acid motifs in both proteins that determine interaction specificity. RAB33B, a Golgi-resident GTPase, also functionally interacts with TRPML3 and contains an LIR motif that specifically binds GATE16. Upon autophagy induction, RAB33B is recruited from the Golgi to the phagophore in an LIR-dependent manner, enhancing the RAB33B-TRPML3 interaction and promoting autophagosome formation.","method":"Co-immunoprecipitation, site-directed mutagenesis, fluorescence microscopy, autophagy flux assays","journal":"Scientific reports","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — co-IP with mutagenesis establishing interaction specificity and functional consequence; single lab, multiple methods","pmids":["40855209"],"is_preprint":false},{"year":2025,"finding":"Alkaline extracellular pH elevates lysosomal pH, which activates the lysosomal Ca2+ channel TRPML3. This TRPML3 activation enhances RNF13 E3 ubiquitin ligase activity, which in turn drives ARL8B degradation and promotes perinuclear lysosomal positioning (retrograde transport).","method":"Lysosomal pH measurements, Ca2+ imaging, TRPML3 channel activity assays, RNF13 activity assays, lysosomal positioning quantification","journal":"bioRxiv","confidence":"Low","confidence_rationale":"Tier 3 / Weak — preprint, single lab, indirect evidence linking TRPML3 activation to downstream pathway effectors","pmids":[],"is_preprint":true}],"current_model":"MCOLN3/TRPML3 is an inwardly rectifying, Ca2+-permeable cation channel with six transmembrane domains that localizes dynamically to the plasma membrane, endoplasmic reticulum, early/late endosomes, lysosomes, and phagophores; its activity is regulated by extracytosolic Na+ (inhibitory), luminal H+ (inhibitory via histidines H252/H273/H283 in the TM1-TM2 loop), and the endolysosomal lipid PtdIns(3,5)P2 (activating via the cytosolic mucolipin/gating-pulley domain), with palmitoylation of its C-terminus controlling trafficking between compartments; gain-of-function mutations (A419P) constitutively open the channel by disrupting TM5 helical structure, causing Ca2+ overload and hair cell death in varitint-waddler mice, while TRPML3 also forms heteromers with TRPML1/TRPML2 (whose localization dictates TRPML3 distribution) and with TRPV5, and functions as a downstream PI3P effector at phagophores and a PtdIns4P-regulated MCOLN1 heteromeric partner at autophagosomes to supply Ca2+ for autophagosome biogenesis and autophagosome-lysosome fusion via the Ca2+ sensor SYT5; it also interacts with GATE16 and RAB33B to promote autophagosome formation, binds FGL2 in neutrophils to trigger autophagy-dependent NET formation, and somatic gain-of-function mutations cause primary aldosteronism by inducing Ca2+ influx and CYP11B2 upregulation in adrenocortical cells."},"narrative":{"mechanistic_narrative":"MCOLN3/TRPML3 is an inwardly rectifying, Ca2+-permeable cation channel that supplies localized Ca2+ to control endolysosomal trafficking and autophagy [PMID:19522758, PMID:36252030]. The wild-type channel is strongly regulated by its ionic and lipid environment: extracytosolic Na+ inhibits the channel and its removal activates it, while luminal H+ inhibits via histidines (H252/H273/H283) in the large TM1-TM2 extracytosolic loop and a negatively charged residue (Glu-361) mediates Na+ block [PMID:17962195, PMID:18369318, PMID:22753890]. Cryo-EM structures define an architecture in which a voltage sensor-like domain connects to the pore through a cytosolic mucolipin domain that binds PtdIns(3,5)P2 to gate the channel as a 'gating pulley', with a luminal polycystin-mucolipin cap that undergoes conformational changes mediating low-pH inhibition and agonists (ML-SA1) opening the S6 gate [PMID:29019979, PMID:29106414]. TRPML3 is dynamically distributed across the plasma membrane, ER, endosomes, lysosomes, and phagophores, and its lysosomal localization is dictated by heteromultimerization with TRPML1/TRPML2; it also forms functional heteromers with TRPV5 [PMID:16606612, PMID:23469151]. Beyond its channel activity, TRPML3 acts as a downstream effector of phosphoinositides in autophagy: PI3P directly activates it at the phagophore to release Ca2+ for autophagosome biogenesis, and a MCOLN1-MCOLN3 heteromer acts downstream of PtdIns4P to release Ca2+ decoded by the sensor SYT5 for autophagosome-lysosome fusion; C-terminal palmitoylation controls starvation-induced trafficking to autophagic structures [PMID:30215288, PMID:36252030, PMID:40413756]. The gain-of-function A419P mutation, which constitutively opens the channel by a helix-breaking proline kink in TM5, causes Ca2+ overload and hair cell death in varitint-waddler mice, an effect suppressed by the plasma membrane Ca2+ pump PMCA2 [PMID:12403827, PMID:18048323, PMID:19299509]. Somatic gain-of-function mutations near the pore drive primary aldosteronism by inducing Ca2+ influx and CYP11B2 upregulation in adrenocortical cells [PMID:40772318].","teleology":[{"year":2002,"claim":"Established MCOLN3/TRPML3 as a putative six-transmembrane cation channel and linked a specific TM5 mutation (A419P) to the varitint-waddler hair cell degeneration phenotype, defining its disease relevance.","evidence":"Positional cloning, sequence analysis, and immunolocalization in hair cells","pmids":["12403827"],"confidence":"High","gaps":["Did not establish channel function or conductance","Mechanism by which A419P causes hair cell death unresolved"]},{"year":2006,"claim":"Resolved the subcellular logic of TRPML targeting by showing TRPML3 homomers reside in the ER but are redirected to lysosomes by heteromultimerization with TRPML1/TRPML2, establishing a localization hierarchy.","evidence":"Reciprocal co-immunoprecipitation, subcellular fractionation, and confocal microscopy with targeting mutants","pmids":["16606612"],"confidence":"High","gaps":["Functional consequence of heteromer assembly on conductance not defined","Stoichiometry of heteromers unknown"]},{"year":2007,"claim":"Defined wild-type TRPML3 biophysics and proved the A419P mutation is gain-of-function, locking an inwardly rectifying channel open via a TM5 helix-breaking kink and causing lethal Ca2+ overload.","evidence":"Whole-cell and single-channel patch-clamp with proline-scan mutagenesis in heterologous and native hair cells","pmids":["18048323","17962195","18162548"],"confidence":"High","gaps":["Physiological activating ligand of the wild-type channel not yet identified","Mechanism coupling Na+ sensing to gating unresolved"]},{"year":2008,"claim":"Identified luminal H+ as a regulator acting through three histidines in the TM1-TM2 loop and showed this regulation communicates with TM5, mechanistically linking the extracytosolic loop to pore gating.","evidence":"Whole-cell patch-clamp with site-directed mutagenesis and pH manipulation","pmids":["18369318"],"confidence":"High","gaps":["Structural path of allosteric coupling between loop and TM5 not visualized","In vivo relevance of pH gating untested at this stage"]},{"year":2008,"claim":"Challenged the constitutive-activity model of deafness by showing TRPML3 mutations reduce mechano-electrical transducer currents and disrupt stereocilia ankle-link localization, implicating a hair-bundle developmental role.","evidence":"MET current recordings, FM1-43 and gentamicin uptake assays, and immunohistochemistry in cochlear hair cells","pmids":["18801844"],"confidence":"Medium","gaps":["Single lab; relative contribution of MET loss vs Ca2+ overload to deafness unresolved","Direct role of TRPML3 in MET channel complex not established"]},{"year":2009,"claim":"Connected TRPML3 to endocytosis and autophagy regulation, and established PMCA2 as a genetic and functional suppressor of TRPML3(A419P)-induced Ca2+ overload, linking channel activity to cell-death control.","evidence":"siRNA knockdown, dominant-negative expression, trafficking/autophagy assays, Ca2+ imaging, and double-mutant mouse genetics","pmids":["19522758","19299509"],"confidence":"Medium","gaps":["Molecular target organelle for TRPML3 Ca2+ delivery in trafficking unclear","Direct interaction between TRPML3 and PMCA2 not demonstrated"]},{"year":2010,"claim":"Showed via clean conditional knockout that TRPML3 loss-of-function alone does not cause auditory/vestibular phenotypes, indicating the varitint-waddler disease arises from gain-of-function rather than absence of channel.","evidence":"Conditional knockout mouse with auditory brainstem response testing and behavioral analysis","pmids":["21179200"],"confidence":"Medium","gaps":["Possible redundancy with TRPML1/TRPML2 not tested","Phenotypes under stress conditions not examined"]},{"year":2010,"claim":"Characterized pharmacological and pore dynamics, identifying synthetic agonists synergizing with low Na+ and a unique A419P pore expansion, while finding native hair cells/melanocytes lack plasma-membrane activator responses.","evidence":"High-throughput fluorescence screen, single-channel and whole-cell electrophysiology, and native cell testing","pmids":["20189104","20378547"],"confidence":"Medium","gaps":["Endogenous agonist not identified","Native localization of TRPML3 outside plasma membrane not directly mapped"]},{"year":2012,"claim":"Mapped Glu-361 in the second extracellular loop as critical for Na+-mediated block, refining the gating model and revealing shared activation mechanisms with TRPML2.","evidence":"Site-directed mutagenesis with whole-cell patch-clamp and pharmacology","pmids":["22753890"],"confidence":"Medium","gaps":["Structural basis of Na+ sensing not resolved at this stage","Physiological Na+ sensing in intact organelles untested"]},{"year":2013,"claim":"Expanded the heteromeric repertoire by demonstrating a TRPML3-TRPV5 heteromeric channel with distinct single-channel properties, indicating combinatorial channel assembly beyond the TRPML family.","evidence":"Co-immunoprecipitation, single-channel patch-clamp, and pharmacology","pmids":["23469151"],"confidence":"Medium","gaps":["Physiological context and tissue where the heteromer forms unknown","Stoichiometry only partially defined"]},{"year":2017,"claim":"Provided high-resolution structural mechanism, revealing the mucolipin/gating-pulley domain as the PtdIns(3,5)P2 sensor and capturing closed, agonist-open, and low-pH inhibited states to explain lipid, agonist, and pH gating.","evidence":"Cryo-EM structures of marmoset and human TRPML3 with functional mutagenesis and electrophysiology","pmids":["29019979","29106414"],"confidence":"High","gaps":["Structures of heteromeric assemblies not determined","Dynamics of conformational transitions in membrane environment not captured"]},{"year":2018,"claim":"Identified C-terminal palmitoylation as the switch enabling starvation-induced trafficking of TRPML3 to autophagic structures, dissociating trafficking regulation from intrinsic channel activity.","evidence":"Mass spectrometry site mapping, palmitoylation inhibitor and hydroxylamine studies, Ca2+ imaging, and autophagy flux assays","pmids":["30215288"],"confidence":"Medium","gaps":["Palmitoyltransferase responsible not identified","Single lab"]},{"year":2022,"claim":"Established TRPML3 as a direct PI3P effector at the phagophore that releases Ca2+ to drive autophagosome biogenesis, and identified an FGL2-MCOLN3 axis triggering autophagy-dependent NET formation in neutrophils.","evidence":"Targeted GCaMP6 Ca2+ reporter imaging, electrophysiology, lipid-binding assays, autophagy assays, and co-IP with knockdown/in vivo models","pmids":["36252030","35926777"],"confidence":"High","gaps":["Structural basis of PI3P binding distinct from PtdIns(3,5)P2 not resolved","FGL2 interaction lacks reciprocal structural validation"]},{"year":2025,"claim":"Defined the autophagosome-lysosome fusion machinery in which a MCOLN1-MCOLN3 heteromer acts downstream of PtdIns4P to release Ca2+ decoded by SYT5, and integrated TRPML3 with GATE16/RAB33B in autophagosome formation.","evidence":"Co-immunoprecipitation, Ca2+ imaging, autophagy flux assays, KO and dominant-negative constructs, and lipid-binding assays","pmids":["40413756","40855209"],"confidence":"Medium","gaps":["Stoichiometry of MCOLN1-MCOLN3 heteromer at fusion sites undefined","Single lab for each interaction"]},{"year":2025,"claim":"Established MCOLN3 as a driver gene for primary aldosteronism, showing pore-region somatic gain-of-function mutations induce Ca2+ influx and CYP11B2 upregulation in adrenocortical cells.","evidence":"NGS of aldosterone-producing adenomas, electrophysiology, fura-2 Ca2+ measurements, gene expression and steroid quantification in transfected cells","pmids":["40772318"],"confidence":"Medium","gaps":["In vivo causation in animal models not demonstrated","Single lab; frequency of these mutations across cohorts unestablished"]},{"year":null,"claim":"The endogenous physiological activator and the in vivo tissue-specific functions of native TRPML3 channels (beyond autophagy and hair cells) remain incompletely defined.","evidence":"","pmids":[],"confidence":"Medium","gaps":["No single endogenous agonist accounting for all native activation defined","Heteromer composition in specific tissues not mapped","Mechanism connecting Ca2+ release to specific downstream sensors only partially resolved"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0005215","term_label":"transporter activity","supporting_discovery_ids":[2,3,17]},{"term_id":"GO:0140299","term_label":"molecular sensor activity","supporting_discovery_ids":[2,4,12]},{"term_id":"GO:0008289","term_label":"lipid binding","supporting_discovery_ids":[14,17]}],"localization":[{"term_id":"GO:0005764","term_label":"lysosome","supporting_discovery_ids":[5,22]},{"term_id":"GO:0005783","term_label":"endoplasmic reticulum","supporting_discovery_ids":[5]},{"term_id":"GO:0005768","term_label":"endosome","supporting_discovery_ids":[7]},{"term_id":"GO:0005886","term_label":"plasma membrane","supporting_discovery_ids":[0,3]},{"term_id":"GO:0031410","term_label":"cytoplasmic vesicle","supporting_discovery_ids":[7,17]}],"pathway":[{"term_id":"R-HSA-9612973","term_label":"Autophagy","supporting_discovery_ids":[7,17,20]},{"term_id":"R-HSA-5653656","term_label":"Vesicle-mediated transport","supporting_discovery_ids":[7]},{"term_id":"R-HSA-1643685","term_label":"Disease","supporting_discovery_ids":[0,19]}],"complexes":["TRPML1-TRPML3 heteromeric channel","TRPML3-TRPV5 heteromeric channel","TRPML1/TRPML2-TRPML3 heteromultimers"],"partners":["MCOLN1","MCOLN2","TRPV5","SYT5","FGL2","RAB33B","GATE16","PMCA2"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"Q8TDD5","full_name":"Mucolipin-3","aliases":["Transient receptor potential channel mucolipin 3","TRPML3"],"length_aa":553,"mass_kda":64.2,"function":"Nonselective cation channel probably playing a role in the regulation of membrane trafficking events. Acts as a Ca(2+)-permeable cation channel with inwardly rectifying activity (PubMed:18369318, PubMed:19497048, PubMed:19522758, PubMed:19885840, PubMed:29106414). Mediates release of Ca(2+) from endosomes to the cytoplasm, contributes to endosomal acidification and is involved in the regulation of membrane trafficking and fusion in the endosomal pathway (PubMed:21245134). Also permeable to Mg(2+), Na(+) and K(+) (By similarity). Does not seem to act as mechanosensory transduction channel in inner ear sensory hair cells. Proposed to play a critical role at the cochlear stereocilia ankle-link region during hair-bundle growth (By similarity). Involved in the regulation of autophagy (PubMed:19522758). Through association with GABARAPL2 may be involved in autophagosome formation possibly providing Ca(2+) for the fusion process (By similarity). Through a possible and probably tissue-specific heteromerization with MCOLN1 may be at least in part involved in many lysosome-dependent cellular events (PubMed:19885840). Possible heteromeric ion channel assemblies with TRPV5 show pharmacological similarity with TRPML3 (PubMed:23469151)","subcellular_location":"Cell membrane; Early endosome membrane; Late endosome membrane; Lysosome membrane; Cytoplasmic vesicle, autophagosome membrane","url":"https://www.uniprot.org/uniprotkb/Q8TDD5/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/MCOLN3","classification":"Not Classified","n_dependent_lines":0,"n_total_lines":1208,"dependency_fraction":0.0},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/MCOLN3","total_profiled":1310},"omim":[{"mim_id":"607400","title":"MUCOLIPIN 3; MCOLN3","url":"https://www.omim.org/entry/607400"},{"mim_id":"607399","title":"MUCOLIPIN 2; MCOLN2","url":"https://www.omim.org/entry/607399"},{"mim_id":"605248","title":"MUCOLIPIN 1; MCOLN1","url":"https://www.omim.org/entry/605248"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"","locations":[],"tissue_specificity":"Group enriched","tissue_distribution":"Detected in many","driving_tissues":[{"tissue":"adrenal gland","ntpm":41.3},{"tissue":"epididymis","ntpm":13.3},{"tissue":"parathyroid gland","ntpm":33.2}],"url":"https://www.proteinatlas.org/search/MCOLN3"},"hgnc":{"alias_symbol":["TRPML3","FLJ11006","TRP-ML3"],"prev_symbol":[]},"alphafold":{"accession":"Q8TDD5","domains":[{"cath_id":"-","chopping":"104-195_205-275","consensus_level":"high","plddt":87.0309,"start":104,"end":275},{"cath_id":"1.20.120","chopping":"53-82_280-395","consensus_level":"high","plddt":90.2226,"start":53,"end":395},{"cath_id":"1.10.287","chopping":"400-528","consensus_level":"high","plddt":92.7819,"start":400,"end":528}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q8TDD5","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q8TDD5-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q8TDD5-F1-predicted_aligned_error_v6.png","plddt_mean":84.25},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=MCOLN3","jax_strain_url":"https://www.jax.org/strain/search?query=MCOLN3"},"sequence":{"accession":"Q8TDD5","fasta_url":"https://rest.uniprot.org/uniprotkb/Q8TDD5.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q8TDD5/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q8TDD5"}},"corpus_meta":[{"pmid":"12403827","id":"PMC_12403827","title":"Mutations 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localization of mouse Trpml3 in stria vascularis, hair cells, and vomeronasal and olfactory receptor neurons.","date":"2011","source":"The Journal of comparative neurology","url":"https://pubmed.ncbi.nlm.nih.gov/21344404","citation_count":25,"is_preprint":false},{"pmid":"17329082","id":"PMC_17329082","title":"TRPML3 and hearing loss in the varitint-waddler mouse.","date":"2007","source":"Biochimica et biophysica acta","url":"https://pubmed.ncbi.nlm.nih.gov/17329082","citation_count":24,"is_preprint":false},{"pmid":"36252030","id":"PMC_36252030","title":"The intracellular Ca2+ channel TRPML3 is a PI3P effector that regulates autophagosome biogenesis.","date":"2022","source":"Proceedings of the National Academy of Sciences of the United States of America","url":"https://pubmed.ncbi.nlm.nih.gov/36252030","citation_count":22,"is_preprint":false},{"pmid":"21179200","id":"PMC_21179200","title":"Genetic inactivation of Trpml3 does not lead to hearing and vestibular impairment in mice.","date":"2010","source":"PloS one","url":"https://pubmed.ncbi.nlm.nih.gov/21179200","citation_count":22,"is_preprint":false},{"pmid":"23469151","id":"PMC_23469151","title":"A novel ion channel formed by interaction of TRPML3 with TRPV5.","date":"2013","source":"PloS one","url":"https://pubmed.ncbi.nlm.nih.gov/23469151","citation_count":21,"is_preprint":false},{"pmid":"20378547","id":"PMC_20378547","title":"Properties of the TRPML3 channel pore and its stable expansion by the Varitint-Waddler-causing mutation.","date":"2010","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/20378547","citation_count":21,"is_preprint":false},{"pmid":"19299509","id":"PMC_19299509","title":"Life and death of sensory hair cells expressing constitutively active TRPML3.","date":"2009","source":"The Journal of biological 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Aldosterone-Producing Adenomas.","date":"2025","source":"Hypertension (Dallas, Tex. : 1979)","url":"https://pubmed.ncbi.nlm.nih.gov/40772318","citation_count":8,"is_preprint":false},{"pmid":"36520788","id":"PMC_36520788","title":"Whole-body analysis of TRPML3 (MCOLN3) expression using a GFP-reporter mouse model reveals widespread expression in secretory cells and endocrine glands.","date":"2022","source":"PloS one","url":"https://pubmed.ncbi.nlm.nih.gov/36520788","citation_count":8,"is_preprint":false},{"pmid":"40348344","id":"PMC_40348344","title":"Targeting TRPML3 inhibits proliferation and invasion, and enhances doxorubicin sensitivity by disrupting lysosomal acidification and mitochondrial function in triple-negative breast cancer.","date":"2025","source":"Biochimica et biophysica acta. Molecular cell research","url":"https://pubmed.ncbi.nlm.nih.gov/40348344","citation_count":1,"is_preprint":false},{"pmid":"40775364","id":"PMC_40775364","title":"TRP channels in hepatocellular carcinoma: integrative Mendelian randomization and multi-omics analyses highlight MCOLN3/TRPV4 as candidate dual-effect biomarkers.","date":"2025","source":"Human genomics","url":"https://pubmed.ncbi.nlm.nih.gov/40775364","citation_count":1,"is_preprint":false},{"pmid":"40682834","id":"PMC_40682834","title":"TRPML3‑mediated lysosomal Ca2+ release enhances drug sequestration and biogenesis, promoting osimertinib resistance in non‑small cell lung cancer.","date":"2025","source":"Oncology reports","url":"https://pubmed.ncbi.nlm.nih.gov/40682834","citation_count":1,"is_preprint":false},{"pmid":"39484451","id":"PMC_39484451","title":"Somatic Mutations in MCOLN3 in Aldosterone-Producing Adenomas cause Primary Aldosteronism.","date":"2024","source":"bioRxiv : the preprint server for biology","url":"https://pubmed.ncbi.nlm.nih.gov/39484451","citation_count":1,"is_preprint":false},{"pmid":"40413756","id":"PMC_40413756","title":"MCOLN1/TRPML1-MCOLN3/TRPML3 heteromer and its coupling to Ca2+ sensor SYT5 regulates autophagosome-lysosome fusion in a PtdIns4P-dependent manner.","date":"2025","source":"Autophagy","url":"https://pubmed.ncbi.nlm.nih.gov/40413756","citation_count":0,"is_preprint":false},{"pmid":"40855209","id":"PMC_40855209","title":"Two specific interactions of GATE16 with TRPML3 and RAB33B regulate autophagy.","date":"2025","source":"Scientific reports","url":"https://pubmed.ncbi.nlm.nih.gov/40855209","citation_count":0,"is_preprint":false},{"pmid":null,"id":"bio_10.1101_2024.10.20.619295","title":"Somatic Mutations in  <i>MCOLN3</i>  in Aldosterone-Producing Adenomas cause Primary Aldosteronism","date":"2024-10-23","source":"bioRxiv","url":"https://doi.org/10.1101/2024.10.20.619295","citation_count":0,"is_preprint":true},{"pmid":null,"id":"bio_10.1101_2025.03.19.644102","title":"RNF13 mediates pH- and Ca  <sup>2+</sup>  -dependent regulation of lysosomal positioning","date":"2025-03-19","source":"bioRxiv","url":"https://doi.org/10.1101/2025.03.19.644102","citation_count":0,"is_preprint":true}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":21201,"output_tokens":6514,"usd":0.080657,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":15191,"output_tokens":5137,"usd":0.10219,"stage2_stop_reason":"end_turn"},"total_usd":0.182847,"stage1_batch_id":"msgbatch_01BbTCMyrRPyhtEq6b1MdwCN","stage2_batch_id":"msgbatch_011dEed5bbxYvTAaQWKJevxu","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2002,\n      \"finding\": \"MCOLN3/TRPML3 encodes a putative six-transmembrane-domain cation channel protein; the Va allele carries an Ala419Pro substitution in the fifth transmembrane domain causing the varitint-waddler phenotype, while the Va(J) allele has an additional Ile362Thr substitution that partially rescues it. TRPML3 localizes to cytoplasmic compartments of hair cells and plasma membrane of stereocilia, with hair cell defects apparent by embryonic day 17.5.\",\n      \"method\": \"Positional cloning, sequence analysis, immunolocalization in hair cells\",\n      \"journal\": \"Proceedings of the National Academy of Sciences of the United States of America\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — positional cloning with direct mutation identification replicated across multiple subsequent studies; localization confirmed by immunofluorescence\",\n      \"pmids\": [\"12403827\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2007,\n      \"finding\": \"The Va mutation A419P in TRPML3 generates a constitutively active cation channel (gain-of-function) by a helix-breaking proline substitution in TM5. Proline substitution scan showed the inner third of TM5 is highly susceptible to proline-based kinks causing constitutive activity; the constitutively active channel was detected as a distinct inwardly rectifying current in native varitint-waddler hair cells.\",\n      \"method\": \"Patch-clamp electrophysiology in heterologous expression and native hair cells; proline substitution scan of TM5\",\n      \"journal\": \"Proceedings of the National Academy of Sciences of the United States of America\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — in vitro electrophysiology plus mutagenesis; replicated in native cells and by multiple independent labs\",\n      \"pmids\": [\"18048323\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2007,\n      \"finding\": \"Wild-type TRPML3 is a strongly inward rectifying cation channel regulated by extracytosolic Na+: pre-incubation in Na+-free medium activates the channel, which then slowly inactivates upon Na+ re-addition. The A419P mutation locks the channel in an open, unregulated state (gain-of-function), affects channel glycosylation, and causes massive cell death. The A419G mutation similarly destabilizes TM5 alpha-helix and produces gain-of-function. I362T results in an inactive channel but does not fully suppress A419P in the double mutant.\",\n      \"method\": \"Whole-cell patch-clamp electrophysiology, site-directed mutagenesis, cell viability assays in heterologous expression system\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — in vitro electrophysiology with systematic mutagenesis, replicated by multiple labs\",\n      \"pmids\": [\"17962195\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2007,\n      \"finding\": \"Wild-type TRPML3 forms channels with conductance of 50–70 pS, opens at very positive potentials (outward rectification). The A419P mutant generates an additional constitutive inwardly rectifying current that depolarizes cells. Cells expressing TRPML3(A419P) or TRPML3(I362T+A419P) die and are extruded from the epithelium, resembling degeneration of Va hair cells.\",\n      \"method\": \"Single-channel and whole-cell patch-clamp in LLC-PK1-CL4 epithelial cells; immunolocalization\",\n      \"journal\": \"Proceedings of the National Academy of Sciences of the United States of America\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — single-channel electrophysiology with mutagenesis; replicated across labs\",\n      \"pmids\": [\"18162548\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2008,\n      \"finding\": \"TRPML3 is a Ca2+-permeable channel uniquely regulated by extracytosolic (luminal) H+ via three histidines (H252, H273, H283) in the large extracytosolic loop between TM1 and TM2. H283A mutation locks the channel open (mimics A419P), while H283R inactivates it. The A419P mutation abolishes H+ regulation, suggesting that the extracytosolic loop communicates with TM5 orientation to control pore opening.\",\n      \"method\": \"Whole-cell patch-clamp electrophysiology, site-directed mutagenesis, pH manipulation\",\n      \"journal\": \"The EMBO journal\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — in vitro electrophysiology with systematic mutagenesis of multiple residues identifying specific regulatory histidines\",\n      \"pmids\": [\"18369318\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2006,\n      \"finding\": \"TRPML proteins form homo- and heteromultimers. TRPML1 and TRPML2 homomultimers are lysosomal, whereas TRPML3 homomultimers localize to the endoplasmic reticulum. However, TRPML3 is redirected to lysosomes when coexpressed with TRPML1 or TRPML2, demonstrating a hierarchy in which TRPML1 and TRPML2 dictate TRPML3 lysosomal localization but not vice versa.\",\n      \"method\": \"Co-immunoprecipitation, subcellular fractionation, confocal microscopy with dominant-negative and lysosomal-targeting mutants\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — reciprocal co-IP plus multiple localization experiments with functional mutants; replicated in subsequent work\",\n      \"pmids\": [\"16606612\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2008,\n      \"finding\": \"TRPML3 mutations (I362T/A419P) cause reduced mechano-electrical transducer (MET) currents in cochlear hair cells, reduced FM1-43 and gentamicin uptake, and loss of TRPML3 localization at the base of stereocilia near ankle links. The study argues TRPML3 plays a critical role at the ankle-link region during hair-bundle growth and that impaired MET is the main cause of hearing loss in Va(J) heterozygotes, rather than constitutive channel activity.\",\n      \"method\": \"Electrophysiological recordings of MET currents, FM1-43 and [3H]gentamicin uptake assays, immunohistochemistry with TRPML3-specific antibody\",\n      \"journal\": \"The Journal of physiology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — direct electrophysiology in native hair cells with antibody localization; single lab, multiple methods\",\n      \"pmids\": [\"18801844\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2009,\n      \"finding\": \"TRPML3 is a prominent regulator of endocytosis, membrane trafficking, and autophagy. Overexpression of TRPML3 reduces constitutive and regulated endocytosis and increases autophagy. Knockdown of TRPML3 by siRNA or expression of a channel-dead dominant-negative TRPML3(D458K) reduces both endocytosis and autophagy. Upon autophagy induction, TRPML3 is dynamically recruited to autophagosomes, suggesting it controls Ca2+ in the vicinity of cellular organelles needed for these events.\",\n      \"method\": \"Gradient fractionation, confocal localization, siRNA knockdown, dominant-negative expression, endocytosis and autophagy assays\",\n      \"journal\": \"Traffic (Copenhagen, Denmark)\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — multiple orthogonal methods (KD, DN, localization, functional assays) in a single lab\",\n      \"pmids\": [\"19522758\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2009,\n      \"finding\": \"PMCA2 (plasma membrane calcium ATPase 2) significantly reduces [Ca2+]i increase and apoptosis in HEK293 cells expressing constitutively active TRPML3(A419P). Genetic epistasis in mice: combining heterozygous Va (TRPML3 A419P) with heterozygous deaf-waddler (PMCA2 G283S) alleles causes severe hair bundle defects and increased hair cell loss compared to single mutants, establishing PMCA2 as a functional suppressor of TRPML3(A419P)-induced Ca2+ overload.\",\n      \"method\": \"Ca2+ imaging, apoptosis assays in HEK293 cells; double-mutant mouse genetics with auditory brainstem responses\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — genetic epistasis in vivo combined with in vitro Ca2+ measurements and functional cell death assay\",\n      \"pmids\": [\"19299509\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2010,\n      \"finding\": \"The TRPML3 pore is dynamic during Ca2+ conduction: it changes conductance and permeability, apparently by trapping Ca2+ within the pore, and can be restored by strong depolarization or Na+ conduction. The A419P mutation results in an expanded channel pore with altered permeability that limits Ca2+-mediated pore modulation; this effect is specific to A419P and is not reproduced by other gain-of-function mutations (A419G, H283A, or other TM5 prolines).\",\n      \"method\": \"Whole-cell and single-channel patch-clamp electrophysiology, site-directed mutagenesis\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — in vitro electrophysiology with mutagenesis, single lab\",\n      \"pmids\": [\"20378547\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2010,\n      \"finding\": \"Genetic inactivation (conditional knockout) of Trpml3 in mice does not lead to hearing loss, vestibular impairment, or circling behavior, establishing that TRPML3 loss-of-function alone is not sufficient to cause auditory/vestibular phenotypes under normal conditions.\",\n      \"method\": \"Conditional knockout mouse, auditory brainstem response testing, behavioral observation\",\n      \"journal\": \"PloS one\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — clean genetic knockout with defined phenotypic readout; single lab but rigorous negative result\",\n      \"pmids\": [\"21179200\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2010,\n      \"finding\": \"TRPML3 can be activated by low extracytosolic sodium and by diverse small molecules identified in a high-throughput screen. Agonists synergize with low extracytosolic [Na+], revealing distinct cooperative activation mechanisms. Testing on native sensory hair cells and melanocytes shows absence of activator-responsive channels, suggesting TRPML3 is absent from the plasma membrane in these native cells or is part of nonresponsive heteromeric channels.\",\n      \"method\": \"High-throughput fluorescence-based screen, electrophysiology, cheminformatics, native cell testing\",\n      \"journal\": \"Chemistry & biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — large screen plus electrophysiological validation; single lab, multiple methods\",\n      \"pmids\": [\"20189104\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"Glu-361 in the second extracellular loop of TRPML3 is critical for sodium-mediated block; mutating this negatively charged residue significantly reduces the sodium inhibition of TRPML3. TRPML2 is also activated by lowering extracellular sodium concentration and by a subset of TRPML3 agonists, suggesting similar gating mechanisms for both channels.\",\n      \"method\": \"Site-directed mutagenesis, whole-cell patch-clamp electrophysiology, pharmacological screening\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — mutagenesis plus electrophysiology; single lab identifying a specific regulatory residue\",\n      \"pmids\": [\"22753890\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"TRPML3 and TRPV5 physically associate to form a novel heteromeric ion channel with pharmacological properties similar to TRPML3 but distinct single-channel features from either homomeric channel. The heteromer requires functional TRPML3 and functional TRPV5, and occurs in potentially distinct stoichiometric configurations.\",\n      \"method\": \"Co-immunoprecipitation, single-channel patch-clamp electrophysiology, pharmacology\",\n      \"journal\": \"PloS one\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — co-IP plus single-channel electrophysiology demonstrating novel conductance; single lab\",\n      \"pmids\": [\"23469151\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"Cryo-EM structure of full-length marmoset TRPML3 at 2.9 Å resolution reveals: (1) a unique architecture where the voltage sensor-like domain is linked to the pore via a cytosolic 'mucolipin domain'; (2) the mucolipin domain is responsible for PtdIns(3,5)P2 binding and channel activation; (3) it acts as a 'gating pulley' for lipid-dependent channel gating. Conserved basic residues at the N-terminus mediate PtdIns(3,5)P2 activation and PtdIns(4,5)P2 inhibition.\",\n      \"method\": \"Cryo-EM structure determination, functional electrophysiology with mutagenesis of basic residues\",\n      \"journal\": \"Nature\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — high-resolution cryo-EM structure plus functional validation by mutagenesis; published in Nature\",\n      \"pmids\": [\"29019979\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"Cryo-EM structures of human TRPML3 in closed, agonist-activated (ML-SA1 bound), and low-pH-inhibited states. The agonist ML-SA1 lodges between S5 and S6 and opens the S6 gate. A polycystin-mucolipin domain (PMD) forms a luminal cap; S1 extends into this cap as a 'gating rod' connected to a luminal pore loop that undergoes dramatic conformational changes at low pH. S2 extends intracellularly forming a 'gating knob'. Low pH induces inhibition by changing S1 and S2 conformations. PIP2 regulation also acts through S1 and S2 conformational changes.\",\n      \"method\": \"Cryo-EM structure determination at 3.62–4.65 Å, electrophysiology, agonist binding studies\",\n      \"journal\": \"Nature structural & molecular biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — three cryo-EM structures capturing distinct functional states combined with electrophysiology; complements marmoset structure in same year\",\n      \"pmids\": [\"29106414\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"MCOLN3/TRPML3 undergoes palmitoylation at its C-terminal region. Palmitoylation is required for dynamic trafficking of MCOLN3 to autophagic structures and for MCOLN3's function in autophagosome formation, but not for channel properties or localization/function of intracellular MCOLN3. Nutrient starvation activates MCOLN3 and increases its palmitoylation level; disruption of palmitoylation abolishes starvation-induced channel activation without affecting intrinsic channel activity.\",\n      \"method\": \"Mass spectrometry for palmitoylation site identification, 2-BP inhibitor studies, hydroxylamine treatment, Ca2+ imaging, autophagy flux assays, shRNA knockdown\",\n      \"journal\": \"Autophagy\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — MS identification of modification site combined with functional palmitoylation inhibition and trafficking assays; single lab, multiple orthogonal methods\",\n      \"pmids\": [\"30215288\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"TRPML3 localizes in phagophores and is a downstream effector of phosphatidylinositol-3-phosphate (PI3P). PI3P directly activates TRPML3 current and Ca2+ release from the phagophore to promote autophagosome biogenesis. TRPML3 physically interacts with PI3P; disruption of this interaction abolishes both PI3P-dependent activation and the increase in autophagy. Inhibition of TRPML3 suppresses autophagy even in the presence of excess PI3P.\",\n      \"method\": \"TRPML3-GCaMP6 targeted reporter Ca2+ imaging, patch-clamp electrophysiology, lipid-binding assays, autophagy flux assays, KO and activation studies\",\n      \"journal\": \"Proceedings of the National Academy of Sciences of the United States of America\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — multiple orthogonal methods (Ca2+ reporter, electrophysiology, lipid binding, genetic loss/gain of function) establishing PI3P as direct TRPML3 activator\",\n      \"pmids\": [\"36252030\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"FGL2 (fibrinogen-like protein 2) directly interacts with mucolipin 3 (MCOLN3/TRPML3) in neutrophils, regulating calcium influx and initiating autophagy that leads to neutrophil extracellular trap (NET) formation. This FGL2-MCOLN3-autophagy axis drives NET-mediated liver injury in fulminant viral hepatitis.\",\n      \"method\": \"Co-immunoprecipitation (direct interaction), adoptive transfer experiments, siRNA/shRNA knockdown, calcium flux assays\",\n      \"journal\": \"Cellular and molecular gastroenterology and hepatology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — co-IP establishing direct interaction plus functional assays in cells and in vivo model; single lab\",\n      \"pmids\": [\"35926777\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"Somatic gain-of-function mutations in MCOLN3 (p.Y391D, p.F415I, p.N411_V412delinsI), located near the ion pore and selectivity filter, cause membrane depolarization and calcium influx in adrenocortical HAC15 cells, triggering increased CYP11B2 (aldosterone synthase) expression and aldosterone production, establishing MCOLN3 as a driver gene for primary aldosteronism.\",\n      \"method\": \"Next-generation sequencing of APAs, electrophysiology, fura-2 calcium measurements, gene expression assays, steroid quantification in transfected adrenocortical cells\",\n      \"journal\": \"Hypertension (Dallas, Tex. : 1979)\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — electrophysiology plus Ca2+ measurements plus downstream gene expression and steroid output in transfected cells; single lab, multiple orthogonal methods\",\n      \"pmids\": [\"40772318\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"MCOLN1/TRPML1 and MCOLN3/TRPML3 form a heteromeric channel that acts downstream of PtdIns4P to release Ca2+ from autophagosomes for autophagosome-lysosome fusion. The Ca2+ signal is decoded by the Ca2+ sensor SYT5 (synaptotagmin 5), which binds both Ca2+ and PtdIns4P to form a fusion complex. Disruption of the MCOLN1-MCOLN3 heteromer or the MCOLN3-SYT5 interaction inhibits autophagosome-lysosome fusion.\",\n      \"method\": \"Co-immunoprecipitation, Ca2+ imaging, autophagy flux assays, KO cells, dominant-negative constructs, lipid-binding assays\",\n      \"journal\": \"Autophagy\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — co-IP, Ca2+ imaging, KO and DN studies establishing heteromeric complex and downstream effector; single lab, multiple orthogonal methods\",\n      \"pmids\": [\"40413756\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"TRPML3 specifically interacts with the mammalian ATG8 homolog GATE16 (but not LC3B) through single amino acid motifs in both proteins that determine interaction specificity. RAB33B, a Golgi-resident GTPase, also functionally interacts with TRPML3 and contains an LIR motif that specifically binds GATE16. Upon autophagy induction, RAB33B is recruited from the Golgi to the phagophore in an LIR-dependent manner, enhancing the RAB33B-TRPML3 interaction and promoting autophagosome formation.\",\n      \"method\": \"Co-immunoprecipitation, site-directed mutagenesis, fluorescence microscopy, autophagy flux assays\",\n      \"journal\": \"Scientific reports\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — co-IP with mutagenesis establishing interaction specificity and functional consequence; single lab, multiple methods\",\n      \"pmids\": [\"40855209\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"Alkaline extracellular pH elevates lysosomal pH, which activates the lysosomal Ca2+ channel TRPML3. This TRPML3 activation enhances RNF13 E3 ubiquitin ligase activity, which in turn drives ARL8B degradation and promotes perinuclear lysosomal positioning (retrograde transport).\",\n      \"method\": \"Lysosomal pH measurements, Ca2+ imaging, TRPML3 channel activity assays, RNF13 activity assays, lysosomal positioning quantification\",\n      \"journal\": \"bioRxiv\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — preprint, single lab, indirect evidence linking TRPML3 activation to downstream pathway effectors\",\n      \"pmids\": [],\n      \"is_preprint\": true\n    }\n  ],\n  \"current_model\": \"MCOLN3/TRPML3 is an inwardly rectifying, Ca2+-permeable cation channel with six transmembrane domains that localizes dynamically to the plasma membrane, endoplasmic reticulum, early/late endosomes, lysosomes, and phagophores; its activity is regulated by extracytosolic Na+ (inhibitory), luminal H+ (inhibitory via histidines H252/H273/H283 in the TM1-TM2 loop), and the endolysosomal lipid PtdIns(3,5)P2 (activating via the cytosolic mucolipin/gating-pulley domain), with palmitoylation of its C-terminus controlling trafficking between compartments; gain-of-function mutations (A419P) constitutively open the channel by disrupting TM5 helical structure, causing Ca2+ overload and hair cell death in varitint-waddler mice, while TRPML3 also forms heteromers with TRPML1/TRPML2 (whose localization dictates TRPML3 distribution) and with TRPV5, and functions as a downstream PI3P effector at phagophores and a PtdIns4P-regulated MCOLN1 heteromeric partner at autophagosomes to supply Ca2+ for autophagosome biogenesis and autophagosome-lysosome fusion via the Ca2+ sensor SYT5; it also interacts with GATE16 and RAB33B to promote autophagosome formation, binds FGL2 in neutrophils to trigger autophagy-dependent NET formation, and somatic gain-of-function mutations cause primary aldosteronism by inducing Ca2+ influx and CYP11B2 upregulation in adrenocortical cells.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"MCOLN3/TRPML3 is an inwardly rectifying, Ca2+-permeable cation channel that supplies localized Ca2+ to control endolysosomal trafficking and autophagy [#7, #17]. The wild-type channel is strongly regulated by its ionic and lipid environment: extracytosolic Na+ inhibits the channel and its removal activates it, while luminal H+ inhibits via histidines (H252/H273/H283) in the large TM1-TM2 extracytosolic loop and a negatively charged residue (Glu-361) mediates Na+ block [#2, #4, #12]. Cryo-EM structures define an architecture in which a voltage sensor-like domain connects to the pore through a cytosolic mucolipin domain that binds PtdIns(3,5)P2 to gate the channel as a 'gating pulley', with a luminal polycystin-mucolipin cap that undergoes conformational changes mediating low-pH inhibition and agonists (ML-SA1) opening the S6 gate [#14, #15]. TRPML3 is dynamically distributed across the plasma membrane, ER, endosomes, lysosomes, and phagophores, and its lysosomal localization is dictated by heteromultimerization with TRPML1/TRPML2; it also forms functional heteromers with TRPV5 [#5, #13]. Beyond its channel activity, TRPML3 acts as a downstream effector of phosphoinositides in autophagy: PI3P directly activates it at the phagophore to release Ca2+ for autophagosome biogenesis, and a MCOLN1-MCOLN3 heteromer acts downstream of PtdIns4P to release Ca2+ decoded by the sensor SYT5 for autophagosome-lysosome fusion; C-terminal palmitoylation controls starvation-induced trafficking to autophagic structures [#16, #17, #20]. The gain-of-function A419P mutation, which constitutively opens the channel by a helix-breaking proline kink in TM5, causes Ca2+ overload and hair cell death in varitint-waddler mice, an effect suppressed by the plasma membrane Ca2+ pump PMCA2 [#0, #1, #8]. Somatic gain-of-function mutations near the pore drive primary aldosteronism by inducing Ca2+ influx and CYP11B2 upregulation in adrenocortical cells [#19].\",\n  \"teleology\": [\n    {\n      \"year\": 2002,\n      \"claim\": \"Established MCOLN3/TRPML3 as a putative six-transmembrane cation channel and linked a specific TM5 mutation (A419P) to the varitint-waddler hair cell degeneration phenotype, defining its disease relevance.\",\n      \"evidence\": \"Positional cloning, sequence analysis, and immunolocalization in hair cells\",\n      \"pmids\": [\"12403827\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not establish channel function or conductance\", \"Mechanism by which A419P causes hair cell death unresolved\"]\n    },\n    {\n      \"year\": 2006,\n      \"claim\": \"Resolved the subcellular logic of TRPML targeting by showing TRPML3 homomers reside in the ER but are redirected to lysosomes by heteromultimerization with TRPML1/TRPML2, establishing a localization hierarchy.\",\n      \"evidence\": \"Reciprocal co-immunoprecipitation, subcellular fractionation, and confocal microscopy with targeting mutants\",\n      \"pmids\": [\"16606612\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Functional consequence of heteromer assembly on conductance not defined\", \"Stoichiometry of heteromers unknown\"]\n    },\n    {\n      \"year\": 2007,\n      \"claim\": \"Defined wild-type TRPML3 biophysics and proved the A419P mutation is gain-of-function, locking an inwardly rectifying channel open via a TM5 helix-breaking kink and causing lethal Ca2+ overload.\",\n      \"evidence\": \"Whole-cell and single-channel patch-clamp with proline-scan mutagenesis in heterologous and native hair cells\",\n      \"pmids\": [\"18048323\", \"17962195\", \"18162548\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Physiological activating ligand of the wild-type channel not yet identified\", \"Mechanism coupling Na+ sensing to gating unresolved\"]\n    },\n    {\n      \"year\": 2008,\n      \"claim\": \"Identified luminal H+ as a regulator acting through three histidines in the TM1-TM2 loop and showed this regulation communicates with TM5, mechanistically linking the extracytosolic loop to pore gating.\",\n      \"evidence\": \"Whole-cell patch-clamp with site-directed mutagenesis and pH manipulation\",\n      \"pmids\": [\"18369318\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Structural path of allosteric coupling between loop and TM5 not visualized\", \"In vivo relevance of pH gating untested at this stage\"]\n    },\n    {\n      \"year\": 2008,\n      \"claim\": \"Challenged the constitutive-activity model of deafness by showing TRPML3 mutations reduce mechano-electrical transducer currents and disrupt stereocilia ankle-link localization, implicating a hair-bundle developmental role.\",\n      \"evidence\": \"MET current recordings, FM1-43 and gentamicin uptake assays, and immunohistochemistry in cochlear hair cells\",\n      \"pmids\": [\"18801844\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Single lab; relative contribution of MET loss vs Ca2+ overload to deafness unresolved\", \"Direct role of TRPML3 in MET channel complex not established\"]\n    },\n    {\n      \"year\": 2009,\n      \"claim\": \"Connected TRPML3 to endocytosis and autophagy regulation, and established PMCA2 as a genetic and functional suppressor of TRPML3(A419P)-induced Ca2+ overload, linking channel activity to cell-death control.\",\n      \"evidence\": \"siRNA knockdown, dominant-negative expression, trafficking/autophagy assays, Ca2+ imaging, and double-mutant mouse genetics\",\n      \"pmids\": [\"19522758\", \"19299509\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Molecular target organelle for TRPML3 Ca2+ delivery in trafficking unclear\", \"Direct interaction between TRPML3 and PMCA2 not demonstrated\"]\n    },\n    {\n      \"year\": 2010,\n      \"claim\": \"Showed via clean conditional knockout that TRPML3 loss-of-function alone does not cause auditory/vestibular phenotypes, indicating the varitint-waddler disease arises from gain-of-function rather than absence of channel.\",\n      \"evidence\": \"Conditional knockout mouse with auditory brainstem response testing and behavioral analysis\",\n      \"pmids\": [\"21179200\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Possible redundancy with TRPML1/TRPML2 not tested\", \"Phenotypes under stress conditions not examined\"]\n    },\n    {\n      \"year\": 2010,\n      \"claim\": \"Characterized pharmacological and pore dynamics, identifying synthetic agonists synergizing with low Na+ and a unique A419P pore expansion, while finding native hair cells/melanocytes lack plasma-membrane activator responses.\",\n      \"evidence\": \"High-throughput fluorescence screen, single-channel and whole-cell electrophysiology, and native cell testing\",\n      \"pmids\": [\"20189104\", \"20378547\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Endogenous agonist not identified\", \"Native localization of TRPML3 outside plasma membrane not directly mapped\"]\n    },\n    {\n      \"year\": 2012,\n      \"claim\": \"Mapped Glu-361 in the second extracellular loop as critical for Na+-mediated block, refining the gating model and revealing shared activation mechanisms with TRPML2.\",\n      \"evidence\": \"Site-directed mutagenesis with whole-cell patch-clamp and pharmacology\",\n      \"pmids\": [\"22753890\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Structural basis of Na+ sensing not resolved at this stage\", \"Physiological Na+ sensing in intact organelles untested\"]\n    },\n    {\n      \"year\": 2013,\n      \"claim\": \"Expanded the heteromeric repertoire by demonstrating a TRPML3-TRPV5 heteromeric channel with distinct single-channel properties, indicating combinatorial channel assembly beyond the TRPML family.\",\n      \"evidence\": \"Co-immunoprecipitation, single-channel patch-clamp, and pharmacology\",\n      \"pmids\": [\"23469151\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Physiological context and tissue where the heteromer forms unknown\", \"Stoichiometry only partially defined\"]\n    },\n    {\n      \"year\": 2017,\n      \"claim\": \"Provided high-resolution structural mechanism, revealing the mucolipin/gating-pulley domain as the PtdIns(3,5)P2 sensor and capturing closed, agonist-open, and low-pH inhibited states to explain lipid, agonist, and pH gating.\",\n      \"evidence\": \"Cryo-EM structures of marmoset and human TRPML3 with functional mutagenesis and electrophysiology\",\n      \"pmids\": [\"29019979\", \"29106414\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Structures of heteromeric assemblies not determined\", \"Dynamics of conformational transitions in membrane environment not captured\"]\n    },\n    {\n      \"year\": 2018,\n      \"claim\": \"Identified C-terminal palmitoylation as the switch enabling starvation-induced trafficking of TRPML3 to autophagic structures, dissociating trafficking regulation from intrinsic channel activity.\",\n      \"evidence\": \"Mass spectrometry site mapping, palmitoylation inhibitor and hydroxylamine studies, Ca2+ imaging, and autophagy flux assays\",\n      \"pmids\": [\"30215288\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Palmitoyltransferase responsible not identified\", \"Single lab\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Established TRPML3 as a direct PI3P effector at the phagophore that releases Ca2+ to drive autophagosome biogenesis, and identified an FGL2-MCOLN3 axis triggering autophagy-dependent NET formation in neutrophils.\",\n      \"evidence\": \"Targeted GCaMP6 Ca2+ reporter imaging, electrophysiology, lipid-binding assays, autophagy assays, and co-IP with knockdown/in vivo models\",\n      \"pmids\": [\"36252030\", \"35926777\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Structural basis of PI3P binding distinct from PtdIns(3,5)P2 not resolved\", \"FGL2 interaction lacks reciprocal structural validation\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Defined the autophagosome-lysosome fusion machinery in which a MCOLN1-MCOLN3 heteromer acts downstream of PtdIns4P to release Ca2+ decoded by SYT5, and integrated TRPML3 with GATE16/RAB33B in autophagosome formation.\",\n      \"evidence\": \"Co-immunoprecipitation, Ca2+ imaging, autophagy flux assays, KO and dominant-negative constructs, and lipid-binding assays\",\n      \"pmids\": [\"40413756\", \"40855209\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Stoichiometry of MCOLN1-MCOLN3 heteromer at fusion sites undefined\", \"Single lab for each interaction\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Established MCOLN3 as a driver gene for primary aldosteronism, showing pore-region somatic gain-of-function mutations induce Ca2+ influx and CYP11B2 upregulation in adrenocortical cells.\",\n      \"evidence\": \"NGS of aldosterone-producing adenomas, electrophysiology, fura-2 Ca2+ measurements, gene expression and steroid quantification in transfected cells\",\n      \"pmids\": [\"40772318\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"In vivo causation in animal models not demonstrated\", \"Single lab; frequency of these mutations across cohorts unestablished\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"The endogenous physiological activator and the in vivo tissue-specific functions of native TRPML3 channels (beyond autophagy and hair cells) remain incompletely defined.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No single endogenous agonist accounting for all native activation defined\", \"Heteromer composition in specific tissues not mapped\", \"Mechanism connecting Ca2+ release to specific downstream sensors only partially resolved\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0005215\", \"supporting_discovery_ids\": [2, 3, 17]},\n      {\"term_id\": \"GO:0140299\", \"supporting_discovery_ids\": [2, 4, 12]},\n      {\"term_id\": \"GO:0008289\", \"supporting_discovery_ids\": [14, 17]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005764\", \"supporting_discovery_ids\": [5, 22]},\n      {\"term_id\": \"GO:0005783\", \"supporting_discovery_ids\": [5]},\n      {\"term_id\": \"GO:0005768\", \"supporting_discovery_ids\": [7]},\n      {\"term_id\": \"GO:0005886\", \"supporting_discovery_ids\": [0, 3]},\n      {\"term_id\": \"GO:0031410\", \"supporting_discovery_ids\": [7, 17]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-9612973\", \"supporting_discovery_ids\": [7, 17, 20]},\n      {\"term_id\": \"R-HSA-5653656\", \"supporting_discovery_ids\": [7]},\n      {\"term_id\": \"R-HSA-1643685\", \"supporting_discovery_ids\": [0, 19]}\n    ],\n    \"complexes\": [\n      \"TRPML1-TRPML3 heteromeric channel\",\n      \"TRPML3-TRPV5 heteromeric channel\",\n      \"TRPML1/TRPML2-TRPML3 heteromultimers\"\n    ],\n    \"partners\": [\n      \"MCOLN1\",\n      \"MCOLN2\",\n      \"TRPV5\",\n      \"SYT5\",\n      \"FGL2\",\n      \"RAB33B\",\n      \"GATE16\",\n      \"PMCA2\"\n    ],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":7,"faith_total":7,"faith_pct":100.0}}