{"gene":"KCNK1","run_date":"2026-06-10T02:59:49","timeline":{"discoveries":[{"year":1996,"finding":"TWIK-1 (KCNK1) is a K+ channel with four transmembrane domains and two pore-forming P domains (novel architecture). Expressed in Xenopus oocytes, it produces time-independent, weakly inward-rectifying currents with a unitary conductance of 34 pS. Inward rectification requires internal Mg2+. Channel activity is up-regulated by protein kinase C activation and down-regulated by internal acidification. Blocked by Ba2+ (IC50=100 µM), quinine (IC50=50 µM), and quinidine (IC50=95 µM).","method":"Heterologous expression in Xenopus oocytes, two-electrode voltage clamp, single-channel recording, pharmacology","journal":"The EMBO journal","confidence":"High","confidence_rationale":"Tier 1 / Strong — direct electrophysiological characterization with multiple orthogonal methods (macroscopic currents, single-channel recording, pharmacological profiling) in the original cloning paper, widely replicated","pmids":["8605869"],"is_preprint":false},{"year":1996,"finding":"TWIK-1 subunits dimerize via an interchain disulfide bridge. A 34-amino-acid domain in the extracellular M1P1 linker loop mediates self-association. Cysteine 69 forms the disulfide bond; replacing C69 with serine abolishes functional K+ channel expression.","method":"Biochemical dimerization assay, site-directed mutagenesis (C69S), functional expression in Xenopus oocytes","journal":"The EMBO journal","confidence":"High","confidence_rationale":"Tier 1 / Strong — mutagenesis combined with biochemical and functional assays in the same study; replicated by subsequent structural and biochemical work","pmids":["8978667"],"is_preprint":false},{"year":1997,"finding":"Native mouse TWIK-1 (mTWIK-1) protein in brain runs at ~81 kDa; treatment with a reducing agent yields a ~40 kDa form, confirming that native subunits dimerize via a disulfide bridge in vivo. In oocytes, mTWIK-1 currents are K+-selective, instantaneous, and weakly inward-rectifying; they are blocked by Ba2+ and quinine, decreased by PKC activation, and increased by internal acidification.","method":"Western blot with/without reducing agent, Xenopus oocyte expression, two-electrode voltage clamp","journal":"FEBS letters","confidence":"High","confidence_rationale":"Tier 1 / Strong — biochemical evidence for in vivo disulfide-linked dimer confirmed by reducing agent treatment, consistent with prior mutagenesis data; multiple orthogonal methods","pmids":["9013852"],"is_preprint":false},{"year":2011,"finding":"In subphysiological extracellular K+ (hypokalemia), human TWIK-1 channels change ion selectivity, becoming permeable to external Na+, and conduct inward leak Na+ currents. Threonine 118 (Thr118) within the pore selectivity sequence TxGYG is required for this altered selectivity. Knockdown of TWIK-1 in human spherical primary cardiac myocytes eliminated paradoxical depolarization in low [K+]o.","method":"Heterologous expression, patch clamp, site-directed mutagenesis (T118), shRNA knockdown in cardiomyocytes, ectopic expression in HL-1 cells","journal":"Science signaling","confidence":"High","confidence_rationale":"Tier 1 / Moderate — mutagenesis identifying specific selectivity-filter residue plus functional knockdown in primary human cardiomyocytes; multiple orthogonal methods in one study","pmids":["21653227"],"is_preprint":false},{"year":2014,"finding":"Native TWIK-1 forms a functional heterodimeric channel with TREK-1 at the plasma membrane of astrocytes, linked by a disulfide bridge between TWIK-1 C69 and TREK-1 C93. Surface expression of TWIK-1 and TREK-1 are interdependent (gene silencing of one reduces surface expression of the other). The TWIK-1/TREK-1 heterodimer mediates astrocytic passive conductance and cannabinoid-induced glutamate release from astrocytes.","method":"Co-immunoprecipitation, pulldown for binding partner identification, site-directed mutagenesis (C69, C93), shRNA gene silencing, electrophysiology in astrocytes, glutamate release assay","journal":"Nature communications","confidence":"High","confidence_rationale":"Tier 2 / Strong — reciprocal Co-IP, mutagenesis of disulfide bond, functional knockdown with defined electrophysiological and secretory phenotypes; multiple orthogonal methods","pmids":["24496152"],"is_preprint":false},{"year":2013,"finding":"TWIK-1 protein is primarily localized in intracellular cytoplasmic fractions (~55%) and mildly hydrophobic internal compartment fractions (~41%) in hippocampal astrocytes, with only ~5% at the plasma membrane. This predominant intracellular retention accounts for the minimal contribution of TWIK-1 to whole-cell passive conductance despite abundant expression.","method":"Subcellular fractionation, TWIK-1 knockout mouse comparison, whole-cell patch clamp in astrocytes","journal":"Frontiers in cellular neuroscience","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — fractionation experiment with KO controls and electrophysiology; single lab but two orthogonal methods","pmids":["24368895"],"is_preprint":false},{"year":2014,"finding":"TWIK-1 is expressed in the soma and proximal dendrites of dentate gyrus granule cells (DGGCs). Gene silencing of TWIK-1 reduces outwardly rectifying K+ current density, causes depolarizing shift in resting membrane potential, enhances firing rate, increases EPSP amplitude, and impairs EPSP-spike coupling in perforant path-to-granule cell synaptic transmission.","method":"Immunolocalization, shRNA gene silencing, whole-cell patch clamp, perforant path stimulation in hippocampal slices","journal":"Molecular brain","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — shRNA knockdown with defined electrophysiological phenotypes and localization; single lab, multiple readouts","pmids":["25406588"],"is_preprint":false},{"year":2015,"finding":"TWIK-1 forms a heterodimeric channel with TASK-3 in dentate gyrus granule cells (DGGCs). The TWIK-1/TASK-3 heterodimer displays outwardly rectifying currents and contributes to intrinsic excitability of DGGCs. Neurotensin-neurotensin receptor 1 (NT-NTSR1) signaling depolarizes DGGCs by inhibiting TWIK-1/TASK-3 heterodimeric channels.","method":"Co-immunoprecipitation, immunohistochemistry, shRNA gene silencing, whole-cell patch clamp, pharmacological NT-NTSR1 activation in hippocampal slices","journal":"Experimental & molecular medicine","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — Co-IP, shRNA knockdown with electrophysiological phenotype, and pharmacological pathway dissection; single lab","pmids":["30416196"],"is_preprint":false},{"year":2019,"finding":"The low intrinsic activity of TWIK-1 is dominated by instability of the selectivity filter (SF) gate in a conductive conformation, rather than by sumoylation, intracellular retention, or a hydrophobic pore barrier. K+ is inefficient at stabilizing an active SF conformation; Rb+, NH4+, and Cs+ promote a pH-dependent activated conformation. Intracellular K+ potently inhibits TWIK-1 Rb+ currents (IC50 = 2.8 mM). Voltage-dependent activation of TWIK-1 via an SF mechanism requires non-physiological strong depolarization.","method":"Heterologous expression, two-electrode voltage clamp in Xenopus oocytes, ion substitution experiments, patch clamp with varied intracellular K+, systematic evaluation of competing gating mechanisms","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1 / Moderate — systematic in vitro channel characterization with multiple ion species, mutagenesis-level mechanistic dissection, and direct testing of competing hypotheses; single lab but rigorous and comprehensive","pmids":["31806709"],"is_preprint":false},{"year":2015,"finding":"Lipid tails from both membrane leaflets can enter fenestrations in the TWIK-1 structure and partially penetrate into the pore, contributing to dewetting. However, dewetting still occurs in the absence of lipid tails; pore hydration is determined primarily by hydrophobic side chains lining the narrowest pore cavity.","method":"Molecular dynamics (MD) simulations using TWIK-1 crystal structure","journal":"Channels (Austin, Tex.)","confidence":"Low","confidence_rationale":"Tier 4 / Weak — computational simulation only, no experimental validation reported in abstract","pmids":["25487004"],"is_preprint":false},{"year":2015,"finding":"mGluR3 activation (Gi/Go-coupled) induces translocation of TWIK-1 channels from intracellular cytoplasm to the plasma membrane surface via a Rab-mediated recycling endosome trafficking pathway. This membrane recruitment enhances NH4+ uptake in hippocampal astrocytes and causes membrane potential depolarization.","method":"Live-cell imaging of TWIK-1 translocation, whole-cell patch clamp, pharmacological mGluR3 activation, TWIK-1 KO astrocytes as controls, Rab-pathway inhibition","journal":"Molecular neurobiology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — direct localization experiment with functional consequence, KO controls, and pathway inhibition; single lab","pmids":["26553349"],"is_preprint":false},{"year":2012,"finding":"TWIK-1 channels heterologously expressed in CHO cells, which are silent in physiological K+ gradients, can conduct large monovalent cation currents when extracellular ionic conditions change, supporting the hypothesis that channel silencing results from gating behavior rather than lack of cell surface expression.","method":"Heterologous expression in CHO cells, patch clamp with varied extracellular ionic conditions","journal":"Biophysical journal","confidence":"Medium","confidence_rationale":"Tier 1 / Weak — direct electrophysiological measurement with controlled ionic substitution; single lab, single method","pmids":["22768960"],"is_preprint":false},{"year":2013,"finding":"Nuclear receptor CAR (constitutive androstane receptor) directly binds a 97-bp response element (−2441/−2345) in the Kcnk1 promoter in male mouse livers upon phenobarbital treatment. This binding is male-specific and requires the pituitary gland. KCNK1 suppresses phenobarbital-induced hepatic hyperplasia, as Kcnk1−/− male mice show further progression of liver hyperplasia.","method":"ChIP assay, Kcnk1 knockout mouse model, promoter-response element mapping, hypophysectomy experiment","journal":"Toxicological sciences","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — ChIP identifying direct promoter binding plus KO mouse phenotype; single lab, two orthogonal methods","pmids":["23291559"],"is_preprint":false},{"year":2016,"finding":"Zebrafish knockdown of kcnk1a or kcnk1b orthologues causes bradycardia and atrial dilation; combined knockdown produces a more severe phenotype that is partially rescued by co-injection of wild-type human KCNK1 mRNA but not by a dominant-negative KCNK1 variant. Both zebrafish and human TWIK-1 channels predominantly localize to the endosomal compartment in transfected cells and produce K+ currents sensitive to external K+ concentration and acidic pH.","method":"Zebrafish morpholino knockdown, mRNA rescue experiments (WT and dominant-negative), two-electrode voltage clamp in Xenopus oocytes, cellular localization in transfected mammalian cells","journal":"Journal of molecular and cellular cardiology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — in vivo knockdown with mRNA rescue, electrophysiology, and localization; single lab but multiple orthogonal methods","pmids":["27103460"],"is_preprint":false},{"year":2016,"finding":"TREK-1 single and TWIK-1/TREK-1 double gene knockout in mice produced no detectable changes in astrocyte passive conductance, resting membrane potential, or membrane input resistance in hippocampal astrocytes in situ. TREK-1 protein was mainly located in intracellular compartments of hippocampus. This negative result challenges the proposed essential contribution of TWIK-1/TREK-1 heterodimers to astrocyte passive conductance.","method":"TREK-1 single KO and TWIK-1/TREK-1 double KO mouse models, whole-cell patch clamp of hippocampal astrocytes in situ, immunofluorescence, qRT-PCR","journal":"Frontiers in cellular neuroscience","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — genetic KO with electrophysiology in situ; single lab but rigorous design with double KO controls; finding is negative/contradictory to other reports","pmids":["26869883"],"is_preprint":false},{"year":2015,"finding":"KCNK1 inhibits osteoclast differentiation induced by RANKL. Overexpression of KCNK1 attenuates RANKL-induced Ca2+ oscillation, JNK activation, and NFATc1 expression; conversely, KCNK1 knockdown enhances osteoclast differentiation, JNK activation, and NFATc1 expression.","method":"Overexpression and shRNA knockdown in osteoclast precursors, Ca2+ imaging, JNK phosphorylation assay, NFATc1 expression assay, osteoclast differentiation assay","journal":"Journal of cell science","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — loss- and gain-of-function with defined molecular pathway readouts; single lab, multiple orthogonal methods","pmids":["26208638"],"is_preprint":false},{"year":2024,"finding":"KCNK1 binds to and activates lactate dehydrogenase A (LDHA) in breast cancer cells, increasing glycolysis and lactate production. This promotes histone lysine lactylation (H3K18 lactylation), which induces downstream gene expression including LDHA itself (positive feedback). Increased LDHA also reduces tumor cell stiffness and adhesion.","method":"Co-immunoprecipitation (KCNK1-LDHA binding), glycolysis/lactate production assays, histone lactylation measurement, siRNA knockdown and overexpression, in vitro and in vivo tumor models","journal":"PLoS biology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — Co-IP identifying non-canonical LDHA binding partner, biochemical activity assays, and functional KD/OE phenotypes; single lab","pmids":["38905316"],"is_preprint":false},{"year":2021,"finding":"AEG-1 (MTDH) directly binds TWIK-1 mRNA as an RNA-binding protein in astrocytes, stabilizing it. AEG-1 knockdown reduces TWIK-1 mRNA and protein levels and decreases TWIK-1-mediated K+ currents; AEG-1 overexpression increases TWIK-1 mRNA stability.","method":"RNA immunoprecipitation (RIP), shRNA knockdown, qPCR, immunocytochemistry, whole-cell patch clamp electrophysiology in astrocytes","journal":"Brain sciences","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — RNA immunoprecipitation demonstrating direct mRNA binding plus functional electrophysiological readout; single lab, multiple methods","pmids":["33440655"],"is_preprint":false},{"year":2020,"finding":"Spadin, an inhibitor of TREK-1, dramatically reduces astrocytic passive conductance in brain slices. Gene silencing experiments demonstrated that spadin-sensitive currents are mediated specifically by TWIK-1/TREK-1 heterodimeric channels in cultured astrocytes and hippocampal astrocytes from brain slices.","method":"Pharmacological inhibition with spadin, shRNA gene silencing of TWIK-1 and TREK-1, whole-cell patch clamp in brain slices and cultured astrocytes","journal":"International journal of molecular sciences","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — pharmacological and genetic loss-of-function with electrophysiological readout; single lab","pmids":["33348878"],"is_preprint":false},{"year":2024,"finding":"KCNK1 siRNA knockdown in IPAH pulmonary arterial smooth muscle cells (PASMCs) suppresses their proliferation and migration, causes membrane depolarization, decreases cytosolic Ca2+, and reduces JNK phosphorylation. Up-regulated KCNK1 in IPAH-PASMCs thus facilitates proliferation/migration via membrane hyperpolarization-dependent Ca2+ signaling and JNK pathway activation.","method":"siRNA knockdown, cell proliferation and migration assays, membrane potential measurement, cytosolic Ca2+ imaging, JNK phosphorylation assay in patient-derived PASMCs","journal":"Frontiers in cardiovascular medicine","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — siRNA KD in patient-derived cells with multiple defined molecular readouts; single lab","pmids":["38410243"],"is_preprint":false},{"year":2024,"finding":"TWIK-1-null mice (exon 1 CRISPR-Cas9 KO) exhibit loss of astrocytic background passive K+ conductance and increased susceptibility to kainic acid-induced seizures, establishing that TWIK-1 mediates astrocytic passive conductance and that its loss promotes neuronal hyperexcitability. The previously used exon 2-deleted mice unexpectedly produce a functional internally deleted TWIK-1 protein.","method":"CRISPR-Cas9 exon 1 knockout mouse, whole-cell patch clamp of astrocytes, kainic acid seizure susceptibility assay, comparison with exon 2-deleted KO mice","journal":"iScience","confidence":"High","confidence_rationale":"Tier 2 / Strong — true null KO with electrophysiology and in vivo seizure phenotype, correcting prior incomplete KO models; multiple readouts in one study","pmids":["39811670"],"is_preprint":false}],"current_model":"KCNK1 (TWIK-1) is a two-pore domain, four-transmembrane-segment background K+ channel that forms covalent homodimers via a C69 disulfide bridge and functional heterodimers with TREK-1 (via C69–C93) and TASK-3; it is predominantly retained in intracellular compartments but can be recruited to the plasma membrane by mGluR3/Rab-mediated trafficking, where it mediates astrocytic passive K+ conductance (loss of which increases seizure susceptibility), contributes to resting membrane potential and intrinsic excitability of dentate granule cells, and displays unique selectivity-filter gating that renders it largely silent for K+ under physiological conditions yet capable of conducting inward Na+ leak currents in hypokalemia through a Thr118-dependent mechanism; beyond ion conduction, KCNK1 can non-canonically bind and activate LDHA to drive glycolytic reprogramming, inhibit osteoclastogenesis via suppression of Ca2+ oscillation and JNK-NFATc1 signaling, and is transcriptionally regulated by nuclear receptor CAR and post-transcriptionally stabilized by the RNA-binding protein AEG-1."},"narrative":{"mechanistic_narrative":"KCNK1 (TWIK-1) is a two-pore-domain, four-transmembrane-segment background K+ channel with a novel architecture that produces time-independent, weakly inward-rectifying currents modulated by PKC and intracellular acidification [PMID:8605869]. Functional channels assemble as disulfide-linked homodimers through Cys69 in the extracellular M1P1 linker, and this bond is required for channel expression and is detectable as a reducing-agent-sensitive ~81 kDa species in native brain [PMID:8978667, PMID:9013852]. The same C69 chemistry allows TWIK-1 to form covalent heterodimers with TREK-1 (C69–C93) and to associate with TASK-3, generating channels with distinct rectification and physiological roles [PMID:24496152, PMID:30416196]. A defining feature of TWIK-1 is its low intrinsic activity, which arises from instability of the selectivity-filter gate rather than from intracellular retention or a hydrophobic pore barrier; K+ poorly stabilizes the conductive conformation, whereas Rb+, NH4+, and Cs+ promote a pH-dependent active state [PMID:31806709]. Under hypokalemia the channel changes selectivity and conducts inward Na+ leak currents through a Thr118-dependent mechanism, driving paradoxical depolarization in cardiomyocytes [PMID:21653227]. TWIK-1 is predominantly intracellular but is recruited to the plasma membrane by Gi/Go-coupled mGluR3 signaling via Rab-dependent recycling endosome trafficking [PMID:24368895, PMID:26553349]. At the astrocyte surface it mediates background passive K+ conductance, and a true null mouse establishes that loss of TWIK-1 abolishes this conductance and increases susceptibility to kainic-acid-induced seizures [PMID:39811670]; it also shapes resting potential and intrinsic excitability of dentate granule cells [PMID:25406588]. Beyond ion conduction, KCNK1 non-canonically binds and activates LDHA to drive glycolytic reprogramming and histone lactylation in breast cancer [PMID:38905316], and modulates Ca2+/JNK signaling to inhibit osteoclastogenesis [PMID:26208638]. Its expression is controlled transcriptionally by the nuclear receptor CAR [PMID:23291559] and post-transcriptionally by the RNA-binding protein AEG-1, which stabilizes TWIK-1 mRNA [PMID:33440655].","teleology":[{"year":1996,"claim":"Established that KCNK1 defines a new K+ channel class, answering what kind of conductance it produces and how it is gated.","evidence":"Heterologous expression in Xenopus oocytes with two-electrode voltage clamp, single-channel recording, and pharmacology","pmids":["8605869"],"confidence":"High","gaps":["No structural basis for inward rectification defined","Native cellular role not yet addressed"]},{"year":1996,"claim":"Defined the assembly mechanism by showing functional channels require a covalent dimer, answering how subunits oligomerize.","evidence":"Biochemical dimerization assay and C69S site-directed mutagenesis with functional expression","pmids":["8978667","9013852"],"confidence":"High","gaps":["Whether C69 also mediates heterodimerization not yet tested","Stoichiometry beyond dimer not addressed"]},{"year":2011,"claim":"Resolved how a 'silent' K+ channel can depolarize cells by demonstrating hypokalemia-induced Na+ permeability through Thr118.","evidence":"Patch clamp with T118 mutagenesis plus shRNA knockdown in primary human cardiomyocytes","pmids":["21653227"],"confidence":"High","gaps":["Physiological contexts where this leak operates beyond cardiomyocytes unclear","Structural mechanism of selectivity switch not solved"]},{"year":2012,"claim":"Clarified the source of channel silencing by showing it reflects gating behavior rather than absent surface expression.","evidence":"Patch clamp of TWIK-1 in CHO cells under varied extracellular ionic conditions","pmids":["22768960"],"confidence":"Medium","gaps":["Single method, single cell line","Molecular identity of the gate not yet defined"]},{"year":2013,"claim":"Identified transcriptional and subcellular determinants of KCNK1 abundance and a hepatic phenotype, addressing how the gene is regulated and what it does outside neurons.","evidence":"ChIP mapping CAR binding to the Kcnk1 promoter and Kcnk1-/- mouse liver hyperplasia analysis; subcellular fractionation in astrocytes","pmids":["23291559","24368895"],"confidence":"Medium","gaps":["Mechanism linking K+ conductance to hyperplasia suppression unknown","Retention/trafficking machinery not identified in these studies"]},{"year":2014,"claim":"Showed KCNK1 functions through heterodimerization, establishing a TWIK-1/TREK-1 channel that carries astrocytic passive conductance.","evidence":"Reciprocal Co-IP, C69/C93 disulfide mutagenesis, shRNA silencing, and astrocyte electrophysiology with glutamate release assay","pmids":["24496152"],"confidence":"High","gaps":["Relative contribution versus homodimers in vivo unresolved","Later genetic studies contested the conductance claim"]},{"year":2014,"claim":"Extended the channel's role to neuronal excitability by defining its impact on granule cell membrane properties.","evidence":"Immunolocalization, shRNA silencing, and patch clamp in hippocampal slices","pmids":["25406588"],"confidence":"Medium","gaps":["Homodimer versus heterodimer identity not resolved here","Knockdown rather than genetic null"]},{"year":2015,"claim":"Identified a second heterodimer partner and a receptor pathway controlling it, showing TWIK-1/TASK-3 sets granule cell excitability under neurotensin signaling.","evidence":"Co-IP, immunohistochemistry, shRNA silencing, and pharmacological NT-NTSR1 activation with patch clamp","pmids":["30416196"],"confidence":"Medium","gaps":["Direct disulfide linkage with TASK-3 not demonstrated","Single lab"]},{"year":2015,"claim":"Revealed non-conduction functions of KCNK1 in bone, addressing whether the channel signals beyond K+ flux.","evidence":"Gain- and loss-of-function in osteoclast precursors with Ca2+ imaging, JNK, and NFATc1 readouts","pmids":["26208638"],"confidence":"Medium","gaps":["Whether ion conduction is required for osteoclast effect unclear","In vivo bone phenotype not tested"]},{"year":2015,"claim":"Probed the structural basis of pore dewetting through simulation of lipid and side-chain contributions to hydration.","evidence":"Molecular dynamics simulations on the TWIK-1 crystal structure","pmids":["25487004"],"confidence":"Low","gaps":["Computational only, no experimental validation","Functional consequence of dewetting not tested in cells"]},{"year":2015,"claim":"Defined how the intracellular pool reaches the surface, showing mGluR3-driven Rab-dependent trafficking recruits TWIK-1 to the membrane.","evidence":"Live-cell imaging of translocation, patch clamp, pharmacological mGluR3 activation, KO controls, and Rab-pathway inhibition","pmids":["26553349"],"confidence":"Medium","gaps":["Specific Rab isoform and adaptors not pinned down","Whether trafficking applies to heterodimers unknown"]},{"year":2016,"claim":"Provided an in vivo organismal phenotype and rescue, addressing the physiological consequence of KCNK1 loss in the heart.","evidence":"Zebrafish morpholino knockdown with WT and dominant-negative human KCNK1 mRNA rescue, oocyte electrophysiology, and localization","pmids":["27103460"],"confidence":"Medium","gaps":["Morpholino off-target effects not fully excluded","Mammalian cardiac requirement not established"]},{"year":2016,"claim":"Challenged the heterodimer-conductance model by showing genetic deletion of TREK-1 and TWIK-1/TREK-1 leaves astrocyte passive conductance intact.","evidence":"TREK-1 single and TWIK-1/TREK-1 double KO mice with in situ astrocyte patch clamp, immunofluorescence, and qRT-PCR","pmids":["26869883"],"confidence":"Medium","gaps":["Discrepancy with knockdown studies unresolved at the time","Possible compensatory channels not excluded"]},{"year":2019,"claim":"Resolved the mechanism of intrinsic silencing, establishing that selectivity-filter gate instability—not retention or a hydrophobic barrier—limits activity.","evidence":"Two-electrode voltage clamp with systematic ion substitution and intracellular K+ variation, testing competing gating hypotheses","pmids":["31806709"],"confidence":"High","gaps":["Physiological permeant ion that activates the SF in vivo unclear","Link between SF gating and Na+ leak under hypokalemia not unified"]},{"year":2020,"claim":"Reinforced the heterodimer conductance model pharmacologically, showing spadin-sensitive currents are mediated by TWIK-1/TREK-1.","evidence":"Spadin inhibition combined with shRNA silencing and patch clamp in slices and cultured astrocytes","pmids":["33348878"],"confidence":"Medium","gaps":["Reconciliation with the negative double-KO result not provided","Spadin specificity for the heterodimer not independently validated"]},{"year":2021,"claim":"Identified post-transcriptional control of KCNK1, showing AEG-1 stabilizes TWIK-1 mRNA to sustain channel function.","evidence":"RNA immunoprecipitation, shRNA knockdown, qPCR, and patch clamp in astrocytes","pmids":["33440655"],"confidence":"Medium","gaps":["Binding site on TWIK-1 mRNA not mapped","Physiological trigger for AEG-1 regulation unknown"]},{"year":2024,"claim":"Uncovered a moonlighting metabolic function, showing KCNK1 binds and activates LDHA to drive glycolysis and histone lactylation in cancer.","evidence":"Co-IP, glycolysis/lactate and histone lactylation assays, knockdown/overexpression, and in vitro/in vivo tumor models","pmids":["38905316"],"confidence":"Medium","gaps":["Whether channel activity contributes to LDHA binding unknown","Structural basis of the KCNK1-LDHA interaction undefined"]},{"year":2024,"claim":"Extended KCNK1's role to vascular smooth muscle, linking the channel to proliferation via Ca2+ and JNK signaling.","evidence":"siRNA knockdown in patient-derived IPAH PASMCs with membrane potential, Ca2+ imaging, and JNK readouts","pmids":["38410243"],"confidence":"Medium","gaps":["Single patient-derived cell system","Causal disease role in IPAH not established in vivo"]},{"year":2024,"claim":"Provided a definitive genetic test using a true null mouse, establishing that TWIK-1 mediates astrocytic passive conductance and protects against seizures, and correcting flawed prior KO models.","evidence":"CRISPR-Cas9 exon 1 knockout mouse with astrocyte patch clamp and kainic acid seizure assay, compared to exon 2-deleted mice","pmids":["39811670"],"confidence":"High","gaps":["Homodimer versus heterodimer basis of the conductance not dissected here","Reconciliation with prior negative TREK-1 double-KO not fully addressed"]},{"year":null,"claim":"How the selectivity-filter gating, the hypokalemia Na+ leak, the trafficking control, and the non-canonical LDHA-binding function are integrated into a single physiological logic remains unresolved.","evidence":"","pmids":[],"confidence":"Medium","gaps":["No unified structural model linking gate instability to Na+ leak","Whether moonlighting LDHA/osteoclast roles require channel conduction is untested","Mendelian disease association via direct genetic evidence absent from the corpus"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0005215","term_label":"transporter activity","supporting_discovery_ids":[0,2,3,8,11]}],"localization":[{"term_id":"GO:0005886","term_label":"plasma membrane","supporting_discovery_ids":[4,10,20]},{"term_id":"GO:0005829","term_label":"cytosol","supporting_discovery_ids":[5,13]},{"term_id":"GO:0005768","term_label":"endosome","supporting_discovery_ids":[10,13]}],"pathway":[{"term_id":"R-HSA-112316","term_label":"Neuronal System","supporting_discovery_ids":[6,7,20]}],"complexes":["TWIK-1/TREK-1 heterodimer","TWIK-1/TASK-3 heterodimer","TWIK-1 homodimer"],"partners":["KCNK2","KCNK9","LDHA","MTDH","NR1I3"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"O00180","full_name":"Potassium channel subfamily K member 1","aliases":["Inward rectifying potassium channel protein TWIK-1","Potassium channel K2P1","Potassium channel KCNO1"],"length_aa":336,"mass_kda":38.1,"function":"Ion channel that contributes to passive transmembrane potassium transport and to the regulation of the resting membrane potential in brain astrocytes, but also in kidney and in other tissues (PubMed:15820677, PubMed:21653227). Forms dimeric channels through which potassium ions pass in accordance with their electrochemical gradient. The channel is selective for K(+) ions at physiological potassium concentrations and at neutral pH, but becomes permeable to Na(+) at subphysiological K(+) levels and upon acidification of the extracellular medium (PubMed:21653227, PubMed:22431633). The homodimer has very low potassium channel activity, when expressed in heterologous systems, and can function as weakly inward rectifying potassium channel (PubMed:15820677, PubMed:21653227, PubMed:22431633, PubMed:23169818, PubMed:25001086, PubMed:8605869, PubMed:8978667). Channel activity is modulated by activation of serotonin receptors (By similarity). Heterodimeric channels containing KCNK1 and KCNK2 have much higher activity, and may represent the predominant form in astrocytes (By similarity). Heterodimeric channels containing KCNK1 and KCNK3 or KCNK9 have much higher activity (PubMed:23169818). Heterodimeric channels formed by KCNK1 and KCNK9 may contribute to halothane-sensitive currents (PubMed:23169818). Mediates outward rectifying potassium currents in dentate gyrus granule cells and contributes to the regulation of their resting membrane potential (By similarity). Contributes to the regulation of action potential firing in dentate gyrus granule cells and down-regulates their intrinsic excitability (By similarity). In astrocytes, the heterodimer formed by KCNK1 and KCNK2 is required for rapid glutamate release in response to activation of G-protein coupled receptors, such as F2R and CNR1 (By similarity). Required for normal ion and water transport in the kidney (By similarity). Contributes to the regulation of the resting membrane potential of pancreatic beta cells (By similarity). The low channel activity of homodimeric KCNK1 may be due to sumoylation (PubMed:15820677, PubMed:20498050, PubMed:23169818). The low channel activity may be due to rapid internalization from the cell membrane and retention in recycling endosomes (PubMed:19959478). Permeable to monovalent cations with ion selectivity for K(+) > Rb(+) >> NH4(+) >> Cs(+) = Na(+) = Li(+)","subcellular_location":"Cell membrane; Recycling endosome; Synaptic cell membrane; Cytoplasmic vesicle; Perikaryon; Cell projection, dendrite; Cell projection; Apical cell membrane","url":"https://www.uniprot.org/uniprotkb/O00180/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/KCNK1","classification":"Not Classified","n_dependent_lines":2,"n_total_lines":1208,"dependency_fraction":0.0016556291390728477},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/KCNK1","total_profiled":1310},"omim":[{"mim_id":"613655","title":"POTASSIUM CHANNEL, SUBFAMILY K, MEMBER 18; KCNK18","url":"https://www.omim.org/entry/613655"},{"mim_id":"611741","title":"ACID-SENSING ION CHANNEL, SUBUNIT 3; ASIC3","url":"https://www.omim.org/entry/611741"},{"mim_id":"611549","title":"SODIUM LEAK CHANNEL, NONSELECTIVE; NALCN","url":"https://www.omim.org/entry/611549"},{"mim_id":"607370","title":"POTASSIUM CHANNEL, SUBFAMILY K, MEMBER 17; KCNK17","url":"https://www.omim.org/entry/607370"},{"mim_id":"606554","title":"EPISODIC ATAXIA, TYPE 3; EA3","url":"https://www.omim.org/entry/606554"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Approved","locations":[{"location":"Vesicles","reliability":"Approved"}],"tissue_specificity":"Tissue enhanced","tissue_distribution":"Detected in many","driving_tissues":[{"tissue":"brain","ntpm":108.6},{"tissue":"choroid plexus","ntpm":70.0}],"url":"https://www.proteinatlas.org/search/KCNK1"},"hgnc":{"alias_symbol":["K2p1.1","DPK","TWIK-1"],"prev_symbol":[]},"alphafold":{"accession":"O00180","domains":[{"cath_id":"-","chopping":"15-88","consensus_level":"medium","plddt":92.0632,"start":15,"end":88},{"cath_id":"1.10.287.70","chopping":"99-281","consensus_level":"medium","plddt":91.8478,"start":99,"end":281}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/O00180","model_url":"https://alphafold.ebi.ac.uk/files/AF-O00180-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-O00180-F1-predicted_aligned_error_v6.png","plddt_mean":82.94},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=KCNK1","jax_strain_url":"https://www.jax.org/strain/search?query=KCNK1"},"sequence":{"accession":"O00180","fasta_url":"https://rest.uniprot.org/uniprotkb/O00180.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/O00180/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/O00180"}},"corpus_meta":[{"pmid":"8605869","id":"PMC_8605869","title":"TWIK-1, a ubiquitous human weakly inward rectifying K+ channel with a novel structure.","date":"1996","source":"The EMBO journal","url":"https://pubmed.ncbi.nlm.nih.gov/8605869","citation_count":434,"is_preprint":false},{"pmid":"19571146","id":"PMC_19571146","title":"TWIK-1 and TREK-1 are potassium channels contributing significantly to astrocyte passive conductance in rat hippocampal slices.","date":"2009","source":"The Journal of neuroscience : the official journal of the Society for Neuroscience","url":"https://pubmed.ncbi.nlm.nih.gov/19571146","citation_count":145,"is_preprint":false},{"pmid":"8978667","id":"PMC_8978667","title":"Dimerization of TWIK-1 K+ channel subunits via a disulfide bridge.","date":"1996","source":"The EMBO journal","url":"https://pubmed.ncbi.nlm.nih.gov/8978667","citation_count":145,"is_preprint":false},{"pmid":"24496152","id":"PMC_24496152","title":"A disulphide-linked heterodimer of TWIK-1 and TREK-1 mediates passive conductance in astrocytes.","date":"2014","source":"Nature communications","url":"https://pubmed.ncbi.nlm.nih.gov/24496152","citation_count":121,"is_preprint":false},{"pmid":"9013852","id":"PMC_9013852","title":"The structure, function and distribution of the mouse TWIK-1 K+ channel.","date":"1997","source":"FEBS letters","url":"https://pubmed.ncbi.nlm.nih.gov/9013852","citation_count":100,"is_preprint":false},{"pmid":"38905316","id":"PMC_38905316","title":"KCNK1 promotes proliferation and metastasis of breast cancer cells by activating lactate dehydrogenase A (LDHA) and up-regulating H3K18 lactylation.","date":"2024","source":"PLoS biology","url":"https://pubmed.ncbi.nlm.nih.gov/38905316","citation_count":76,"is_preprint":false},{"pmid":"21653227","id":"PMC_21653227","title":"TWIK-1 two-pore domain potassium channels change ion selectivity and conduct inward leak sodium currents in hypokalemia.","date":"2011","source":"Science signaling","url":"https://pubmed.ncbi.nlm.nih.gov/21653227","citation_count":66,"is_preprint":false},{"pmid":"30416196","id":"PMC_30416196","title":"TWIK-1/TASK-3 heterodimeric channels contribute to the neurotensin-mediated excitation of hippocampal dentate gyrus granule cells.","date":"2018","source":"Experimental & molecular medicine","url":"https://pubmed.ncbi.nlm.nih.gov/30416196","citation_count":65,"is_preprint":false},{"pmid":"16025300","id":"PMC_16025300","title":"Expression and insights on function of potassium channel TWIK-1 in mouse kidney.","date":"2005","source":"Pflugers Archiv : European journal of physiology","url":"https://pubmed.ncbi.nlm.nih.gov/16025300","citation_count":43,"is_preprint":false},{"pmid":"26869883","id":"PMC_26869883","title":"Genetic Deletion of TREK-1 or TWIK-1/TREK-1 Potassium Channels does not Alter the Basic Electrophysiological Properties of Mature Hippocampal Astrocytes In Situ.","date":"2016","source":"Frontiers in cellular neuroscience","url":"https://pubmed.ncbi.nlm.nih.gov/26869883","citation_count":37,"is_preprint":false},{"pmid":"9843722","id":"PMC_9843722","title":"Expression of TWIK-1, a novel weakly inward rectifying potassium channel in rat kidney.","date":"1998","source":"The American journal of physiology","url":"https://pubmed.ncbi.nlm.nih.gov/9843722","citation_count":36,"is_preprint":false},{"pmid":"24368895","id":"PMC_24368895","title":"The contribution of TWIK-1 channels to astrocyte K(+) current is limited by retention in intracellular compartments.","date":"2013","source":"Frontiers in cellular neuroscience","url":"https://pubmed.ncbi.nlm.nih.gov/24368895","citation_count":33,"is_preprint":false},{"pmid":"9362344","id":"PMC_9362344","title":"Cloning and localization of a double-pore K channel, KCNK1: exclusive expression in distal nephron segments.","date":"1997","source":"The American journal of physiology","url":"https://pubmed.ncbi.nlm.nih.gov/9362344","citation_count":31,"is_preprint":false},{"pmid":"27103460","id":"PMC_27103460","title":"The two-pore domain potassium channel, TWIK-1, has a role in the regulation of heart rate and atrial size.","date":"2016","source":"Journal of molecular and cellular cardiology","url":"https://pubmed.ncbi.nlm.nih.gov/27103460","citation_count":30,"is_preprint":false},{"pmid":"31806709","id":"PMC_31806709","title":"Selectivity filter instability dominates the low intrinsic activity of the TWIK-1 K2P K+ channel.","date":"2019","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/31806709","citation_count":23,"is_preprint":false},{"pmid":"25487004","id":"PMC_25487004","title":"Influence of lipids on the hydrophobic barrier within the pore of the TWIK-1 K2P channel.","date":"2015","source":"Channels (Austin, Tex.)","url":"https://pubmed.ncbi.nlm.nih.gov/25487004","citation_count":23,"is_preprint":false},{"pmid":"25406588","id":"PMC_25406588","title":"TWIK-1 contributes to the intrinsic excitability of dentate granule cells in mouse hippocampus.","date":"2014","source":"Molecular brain","url":"https://pubmed.ncbi.nlm.nih.gov/25406588","citation_count":22,"is_preprint":false},{"pmid":"12855359","id":"PMC_12855359","title":"Cellular localization of TWIK-1, a two-pore-domain potassium channel in the rodent inner ear.","date":"2003","source":"Hearing research","url":"https://pubmed.ncbi.nlm.nih.gov/12855359","citation_count":20,"is_preprint":false},{"pmid":"16847696","id":"PMC_16847696","title":"Adaptive downregulation of a quinidine-sensitive cation conductance in renal principal cells of TWIK-1 knockout mice.","date":"2006","source":"Pflugers Archiv : European journal of physiology","url":"https://pubmed.ncbi.nlm.nih.gov/16847696","citation_count":17,"is_preprint":false},{"pmid":"22768960","id":"PMC_22768960","title":"Silent TWIK-1 potassium channels conduct monovalent cation currents.","date":"2012","source":"Biophysical journal","url":"https://pubmed.ncbi.nlm.nih.gov/22768960","citation_count":16,"is_preprint":false},{"pmid":"26208638","id":"PMC_26208638","title":"KCNK1 inhibits osteoclastogenesis by blocking the Ca2+ oscillation and JNK-NFATc1 signaling axis.","date":"2015","source":"Journal of cell science","url":"https://pubmed.ncbi.nlm.nih.gov/26208638","citation_count":14,"is_preprint":false},{"pmid":"23291559","id":"PMC_23291559","title":"Nuclear receptor CAR specifically activates the two-pore K+ channel Kcnk1 gene in male mouse livers, which attenuates phenobarbital-induced hepatic hyperplasia.","date":"2013","source":"Toxicological sciences : an official journal of the Society of Toxicology","url":"https://pubmed.ncbi.nlm.nih.gov/23291559","citation_count":14,"is_preprint":false},{"pmid":"26553349","id":"PMC_26553349","title":"mGluR3 Activation Recruits Cytoplasmic TWIK-1 Channels to Membrane that Enhances Ammonium Uptake in Hippocampal Astrocytes.","date":"2015","source":"Molecular neurobiology","url":"https://pubmed.ncbi.nlm.nih.gov/26553349","citation_count":12,"is_preprint":false},{"pmid":"38410243","id":"PMC_38410243","title":"Up-regulated expression of two-pore domain K+ channels, KCNK1 and KCNK2, is involved in the proliferation and migration of pulmonary arterial smooth muscle cells in pulmonary arterial hypertension.","date":"2024","source":"Frontiers in cardiovascular medicine","url":"https://pubmed.ncbi.nlm.nih.gov/38410243","citation_count":11,"is_preprint":false},{"pmid":"27558721","id":"PMC_27558721","title":"Exploring the Dynamics of the TWIK-1 Channel.","date":"2016","source":"Biophysical journal","url":"https://pubmed.ncbi.nlm.nih.gov/27558721","citation_count":11,"is_preprint":false},{"pmid":"33348878","id":"PMC_33348878","title":"Spadin Modulates Astrocytic Passive Conductance via Inhibition of TWIK-1/TREK-1 Heterodimeric Channels.","date":"2020","source":"International journal of molecular sciences","url":"https://pubmed.ncbi.nlm.nih.gov/33348878","citation_count":10,"is_preprint":false},{"pmid":"29295556","id":"PMC_29295556","title":"Emerging Roles of TWIK-1 Heterodimerization in the Brain.","date":"2017","source":"International journal of molecular sciences","url":"https://pubmed.ncbi.nlm.nih.gov/29295556","citation_count":9,"is_preprint":false},{"pmid":"37144575","id":"PMC_37144575","title":"Downregulation of ciRNA-Kat6b in dorsal spinal horn is required for neuropathic pain by regulating Kcnk1 in miRNA-26a-dependent manner.","date":"2023","source":"CNS neuroscience & therapeutics","url":"https://pubmed.ncbi.nlm.nih.gov/37144575","citation_count":9,"is_preprint":false},{"pmid":"38689322","id":"PMC_38689322","title":"Overexpressed KCNK1 regulates potassium channels affecting molecular mechanisms and biological pathways in bladder cancer.","date":"2024","source":"European journal of medical research","url":"https://pubmed.ncbi.nlm.nih.gov/38689322","citation_count":6,"is_preprint":false},{"pmid":"34685731","id":"PMC_34685731","title":"TWIK-1 BAC-GFP Transgenic Mice, an Animal Model for TWIK-1 Expression.","date":"2021","source":"Cells","url":"https://pubmed.ncbi.nlm.nih.gov/34685731","citation_count":4,"is_preprint":false},{"pmid":"37005754","id":"PMC_37005754","title":"The Effect of TWIK-1 Two Pore Potassium Channels on Cardiomyocytes in Low Extracellular Potassium Conditions.","date":"2023","source":"Frontiers in bioscience (Landmark edition)","url":"https://pubmed.ncbi.nlm.nih.gov/37005754","citation_count":4,"is_preprint":false},{"pmid":"33440655","id":"PMC_33440655","title":"AEG-1 Regulates TWIK-1 Expression as an RNA-Binding Protein in Astrocytes.","date":"2021","source":"Brain sciences","url":"https://pubmed.ncbi.nlm.nih.gov/33440655","citation_count":1,"is_preprint":false},{"pmid":"39012638","id":"PMC_39012638","title":"Evidence for an Association Between a pH-Dependent Potassium Channel, TWIK-1, and the Accuracy of Smooth Pursuit Eye Movements.","date":"2024","source":"Investigative ophthalmology & visual science","url":"https://pubmed.ncbi.nlm.nih.gov/39012638","citation_count":1,"is_preprint":false},{"pmid":"41155507","id":"PMC_41155507","title":"Genetic Variants in SDC3, KCNA2, KCNK1, KCNK16, and Heat Shock Transcription Factor-1 Genes: An Exploratory Analysis Supporting the Piezo2 Channelopathy Hypothesis in Amyotrophic Lateral Sclerosis Onset.","date":"2025","source":"International journal of molecular sciences","url":"https://pubmed.ncbi.nlm.nih.gov/41155507","citation_count":1,"is_preprint":false},{"pmid":"39639713","id":"PMC_39639713","title":"Exploring the Role of the KCNK1 Potassium Channel and Its Inhibition Using Quinidine in Treating Head and Neck Squamous Cell Carcinoma.","date":"2024","source":"Clinical and experimental otorhinolaryngology","url":"https://pubmed.ncbi.nlm.nih.gov/39639713","citation_count":0,"is_preprint":false},{"pmid":"39811670","id":"PMC_39811670","title":"Mice deficient in TWIK-1 are more susceptible to kainic acid-induced seizures.","date":"2024","source":"iScience","url":"https://pubmed.ncbi.nlm.nih.gov/39811670","citation_count":0,"is_preprint":false},{"pmid":"41386584","id":"PMC_41386584","title":"The preference for ammonium may be attributed to a hyperpolarized membrane potential via TWIK-1 channels.","date":"2025","source":"Brain research","url":"https://pubmed.ncbi.nlm.nih.gov/41386584","citation_count":0,"is_preprint":false},{"pmid":null,"id":"bio_10.1101_2025.10.06.680680","title":"Temperature and pH-dependent Potassium Currents of Muscles of the Stomatogastric Nervous System of the Crab,  <i>Cancer borealis</i>","date":"2025-10-07","source":"bioRxiv","url":"https://doi.org/10.1101/2025.10.06.680680","citation_count":0,"is_preprint":true},{"pmid":null,"id":"bio_10.1101_2025.04.23.650279","title":"Structural basis for proton inhibition of the two-pore domain K  <sup>+</sup>  channel TASK-1","date":"2025-04-26","source":"bioRxiv","url":"https://doi.org/10.1101/2025.04.23.650279","citation_count":0,"is_preprint":true},{"pmid":null,"id":"bio_10.1101_2025.04.11.647636","title":"A ketogenic diet mitigates hippocampal astrogliosis in epileptic brain","date":"2025-04-12","source":"bioRxiv","url":"https://doi.org/10.1101/2025.04.11.647636","citation_count":0,"is_preprint":true},{"pmid":null,"id":"bio_10.1101_2025.01.08.631886","title":"Atomistic Mechanism of Non-Canonical Voltage Gating in TREK K  <sub>2P</sub>  Channels","date":"2025-01-10","source":"bioRxiv","url":"https://doi.org/10.1101/2025.01.08.631886","citation_count":0,"is_preprint":true}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":22601,"output_tokens":5729,"usd":0.076869,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":14333,"output_tokens":5275,"usd":0.10177,"stage2_stop_reason":"end_turn"},"total_usd":0.178639,"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\": 1996,\n      \"finding\": \"TWIK-1 (KCNK1) is a K+ channel with four transmembrane domains and two pore-forming P domains (novel architecture). Expressed in Xenopus oocytes, it produces time-independent, weakly inward-rectifying currents with a unitary conductance of 34 pS. Inward rectification requires internal Mg2+. Channel activity is up-regulated by protein kinase C activation and down-regulated by internal acidification. Blocked by Ba2+ (IC50=100 µM), quinine (IC50=50 µM), and quinidine (IC50=95 µM).\",\n      \"method\": \"Heterologous expression in Xenopus oocytes, two-electrode voltage clamp, single-channel recording, pharmacology\",\n      \"journal\": \"The EMBO journal\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — direct electrophysiological characterization with multiple orthogonal methods (macroscopic currents, single-channel recording, pharmacological profiling) in the original cloning paper, widely replicated\",\n      \"pmids\": [\"8605869\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1996,\n      \"finding\": \"TWIK-1 subunits dimerize via an interchain disulfide bridge. A 34-amino-acid domain in the extracellular M1P1 linker loop mediates self-association. Cysteine 69 forms the disulfide bond; replacing C69 with serine abolishes functional K+ channel expression.\",\n      \"method\": \"Biochemical dimerization assay, site-directed mutagenesis (C69S), functional expression in Xenopus oocytes\",\n      \"journal\": \"The EMBO journal\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — mutagenesis combined with biochemical and functional assays in the same study; replicated by subsequent structural and biochemical work\",\n      \"pmids\": [\"8978667\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1997,\n      \"finding\": \"Native mouse TWIK-1 (mTWIK-1) protein in brain runs at ~81 kDa; treatment with a reducing agent yields a ~40 kDa form, confirming that native subunits dimerize via a disulfide bridge in vivo. In oocytes, mTWIK-1 currents are K+-selective, instantaneous, and weakly inward-rectifying; they are blocked by Ba2+ and quinine, decreased by PKC activation, and increased by internal acidification.\",\n      \"method\": \"Western blot with/without reducing agent, Xenopus oocyte expression, two-electrode voltage clamp\",\n      \"journal\": \"FEBS letters\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — biochemical evidence for in vivo disulfide-linked dimer confirmed by reducing agent treatment, consistent with prior mutagenesis data; multiple orthogonal methods\",\n      \"pmids\": [\"9013852\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2011,\n      \"finding\": \"In subphysiological extracellular K+ (hypokalemia), human TWIK-1 channels change ion selectivity, becoming permeable to external Na+, and conduct inward leak Na+ currents. Threonine 118 (Thr118) within the pore selectivity sequence TxGYG is required for this altered selectivity. Knockdown of TWIK-1 in human spherical primary cardiac myocytes eliminated paradoxical depolarization in low [K+]o.\",\n      \"method\": \"Heterologous expression, patch clamp, site-directed mutagenesis (T118), shRNA knockdown in cardiomyocytes, ectopic expression in HL-1 cells\",\n      \"journal\": \"Science signaling\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — mutagenesis identifying specific selectivity-filter residue plus functional knockdown in primary human cardiomyocytes; multiple orthogonal methods in one study\",\n      \"pmids\": [\"21653227\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"Native TWIK-1 forms a functional heterodimeric channel with TREK-1 at the plasma membrane of astrocytes, linked by a disulfide bridge between TWIK-1 C69 and TREK-1 C93. Surface expression of TWIK-1 and TREK-1 are interdependent (gene silencing of one reduces surface expression of the other). The TWIK-1/TREK-1 heterodimer mediates astrocytic passive conductance and cannabinoid-induced glutamate release from astrocytes.\",\n      \"method\": \"Co-immunoprecipitation, pulldown for binding partner identification, site-directed mutagenesis (C69, C93), shRNA gene silencing, electrophysiology in astrocytes, glutamate release assay\",\n      \"journal\": \"Nature communications\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — reciprocal Co-IP, mutagenesis of disulfide bond, functional knockdown with defined electrophysiological and secretory phenotypes; multiple orthogonal methods\",\n      \"pmids\": [\"24496152\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"TWIK-1 protein is primarily localized in intracellular cytoplasmic fractions (~55%) and mildly hydrophobic internal compartment fractions (~41%) in hippocampal astrocytes, with only ~5% at the plasma membrane. This predominant intracellular retention accounts for the minimal contribution of TWIK-1 to whole-cell passive conductance despite abundant expression.\",\n      \"method\": \"Subcellular fractionation, TWIK-1 knockout mouse comparison, whole-cell patch clamp in astrocytes\",\n      \"journal\": \"Frontiers in cellular neuroscience\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — fractionation experiment with KO controls and electrophysiology; single lab but two orthogonal methods\",\n      \"pmids\": [\"24368895\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"TWIK-1 is expressed in the soma and proximal dendrites of dentate gyrus granule cells (DGGCs). Gene silencing of TWIK-1 reduces outwardly rectifying K+ current density, causes depolarizing shift in resting membrane potential, enhances firing rate, increases EPSP amplitude, and impairs EPSP-spike coupling in perforant path-to-granule cell synaptic transmission.\",\n      \"method\": \"Immunolocalization, shRNA gene silencing, whole-cell patch clamp, perforant path stimulation in hippocampal slices\",\n      \"journal\": \"Molecular brain\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — shRNA knockdown with defined electrophysiological phenotypes and localization; single lab, multiple readouts\",\n      \"pmids\": [\"25406588\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"TWIK-1 forms a heterodimeric channel with TASK-3 in dentate gyrus granule cells (DGGCs). The TWIK-1/TASK-3 heterodimer displays outwardly rectifying currents and contributes to intrinsic excitability of DGGCs. Neurotensin-neurotensin receptor 1 (NT-NTSR1) signaling depolarizes DGGCs by inhibiting TWIK-1/TASK-3 heterodimeric channels.\",\n      \"method\": \"Co-immunoprecipitation, immunohistochemistry, shRNA gene silencing, whole-cell patch clamp, pharmacological NT-NTSR1 activation in hippocampal slices\",\n      \"journal\": \"Experimental & molecular medicine\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — Co-IP, shRNA knockdown with electrophysiological phenotype, and pharmacological pathway dissection; single lab\",\n      \"pmids\": [\"30416196\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"The low intrinsic activity of TWIK-1 is dominated by instability of the selectivity filter (SF) gate in a conductive conformation, rather than by sumoylation, intracellular retention, or a hydrophobic pore barrier. K+ is inefficient at stabilizing an active SF conformation; Rb+, NH4+, and Cs+ promote a pH-dependent activated conformation. Intracellular K+ potently inhibits TWIK-1 Rb+ currents (IC50 = 2.8 mM). Voltage-dependent activation of TWIK-1 via an SF mechanism requires non-physiological strong depolarization.\",\n      \"method\": \"Heterologous expression, two-electrode voltage clamp in Xenopus oocytes, ion substitution experiments, patch clamp with varied intracellular K+, systematic evaluation of competing gating mechanisms\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — systematic in vitro channel characterization with multiple ion species, mutagenesis-level mechanistic dissection, and direct testing of competing hypotheses; single lab but rigorous and comprehensive\",\n      \"pmids\": [\"31806709\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"Lipid tails from both membrane leaflets can enter fenestrations in the TWIK-1 structure and partially penetrate into the pore, contributing to dewetting. However, dewetting still occurs in the absence of lipid tails; pore hydration is determined primarily by hydrophobic side chains lining the narrowest pore cavity.\",\n      \"method\": \"Molecular dynamics (MD) simulations using TWIK-1 crystal structure\",\n      \"journal\": \"Channels (Austin, Tex.)\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 4 / Weak — computational simulation only, no experimental validation reported in abstract\",\n      \"pmids\": [\"25487004\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"mGluR3 activation (Gi/Go-coupled) induces translocation of TWIK-1 channels from intracellular cytoplasm to the plasma membrane surface via a Rab-mediated recycling endosome trafficking pathway. This membrane recruitment enhances NH4+ uptake in hippocampal astrocytes and causes membrane potential depolarization.\",\n      \"method\": \"Live-cell imaging of TWIK-1 translocation, whole-cell patch clamp, pharmacological mGluR3 activation, TWIK-1 KO astrocytes as controls, Rab-pathway inhibition\",\n      \"journal\": \"Molecular neurobiology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — direct localization experiment with functional consequence, KO controls, and pathway inhibition; single lab\",\n      \"pmids\": [\"26553349\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"TWIK-1 channels heterologously expressed in CHO cells, which are silent in physiological K+ gradients, can conduct large monovalent cation currents when extracellular ionic conditions change, supporting the hypothesis that channel silencing results from gating behavior rather than lack of cell surface expression.\",\n      \"method\": \"Heterologous expression in CHO cells, patch clamp with varied extracellular ionic conditions\",\n      \"journal\": \"Biophysical journal\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 1 / Weak — direct electrophysiological measurement with controlled ionic substitution; single lab, single method\",\n      \"pmids\": [\"22768960\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"Nuclear receptor CAR (constitutive androstane receptor) directly binds a 97-bp response element (−2441/−2345) in the Kcnk1 promoter in male mouse livers upon phenobarbital treatment. This binding is male-specific and requires the pituitary gland. KCNK1 suppresses phenobarbital-induced hepatic hyperplasia, as Kcnk1−/− male mice show further progression of liver hyperplasia.\",\n      \"method\": \"ChIP assay, Kcnk1 knockout mouse model, promoter-response element mapping, hypophysectomy experiment\",\n      \"journal\": \"Toxicological sciences\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — ChIP identifying direct promoter binding plus KO mouse phenotype; single lab, two orthogonal methods\",\n      \"pmids\": [\"23291559\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"Zebrafish knockdown of kcnk1a or kcnk1b orthologues causes bradycardia and atrial dilation; combined knockdown produces a more severe phenotype that is partially rescued by co-injection of wild-type human KCNK1 mRNA but not by a dominant-negative KCNK1 variant. Both zebrafish and human TWIK-1 channels predominantly localize to the endosomal compartment in transfected cells and produce K+ currents sensitive to external K+ concentration and acidic pH.\",\n      \"method\": \"Zebrafish morpholino knockdown, mRNA rescue experiments (WT and dominant-negative), two-electrode voltage clamp in Xenopus oocytes, cellular localization in transfected mammalian cells\",\n      \"journal\": \"Journal of molecular and cellular cardiology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — in vivo knockdown with mRNA rescue, electrophysiology, and localization; single lab but multiple orthogonal methods\",\n      \"pmids\": [\"27103460\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"TREK-1 single and TWIK-1/TREK-1 double gene knockout in mice produced no detectable changes in astrocyte passive conductance, resting membrane potential, or membrane input resistance in hippocampal astrocytes in situ. TREK-1 protein was mainly located in intracellular compartments of hippocampus. This negative result challenges the proposed essential contribution of TWIK-1/TREK-1 heterodimers to astrocyte passive conductance.\",\n      \"method\": \"TREK-1 single KO and TWIK-1/TREK-1 double KO mouse models, whole-cell patch clamp of hippocampal astrocytes in situ, immunofluorescence, qRT-PCR\",\n      \"journal\": \"Frontiers in cellular neuroscience\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — genetic KO with electrophysiology in situ; single lab but rigorous design with double KO controls; finding is negative/contradictory to other reports\",\n      \"pmids\": [\"26869883\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"KCNK1 inhibits osteoclast differentiation induced by RANKL. Overexpression of KCNK1 attenuates RANKL-induced Ca2+ oscillation, JNK activation, and NFATc1 expression; conversely, KCNK1 knockdown enhances osteoclast differentiation, JNK activation, and NFATc1 expression.\",\n      \"method\": \"Overexpression and shRNA knockdown in osteoclast precursors, Ca2+ imaging, JNK phosphorylation assay, NFATc1 expression assay, osteoclast differentiation assay\",\n      \"journal\": \"Journal of cell science\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — loss- and gain-of-function with defined molecular pathway readouts; single lab, multiple orthogonal methods\",\n      \"pmids\": [\"26208638\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"KCNK1 binds to and activates lactate dehydrogenase A (LDHA) in breast cancer cells, increasing glycolysis and lactate production. This promotes histone lysine lactylation (H3K18 lactylation), which induces downstream gene expression including LDHA itself (positive feedback). Increased LDHA also reduces tumor cell stiffness and adhesion.\",\n      \"method\": \"Co-immunoprecipitation (KCNK1-LDHA binding), glycolysis/lactate production assays, histone lactylation measurement, siRNA knockdown and overexpression, in vitro and in vivo tumor models\",\n      \"journal\": \"PLoS biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — Co-IP identifying non-canonical LDHA binding partner, biochemical activity assays, and functional KD/OE phenotypes; single lab\",\n      \"pmids\": [\"38905316\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"AEG-1 (MTDH) directly binds TWIK-1 mRNA as an RNA-binding protein in astrocytes, stabilizing it. AEG-1 knockdown reduces TWIK-1 mRNA and protein levels and decreases TWIK-1-mediated K+ currents; AEG-1 overexpression increases TWIK-1 mRNA stability.\",\n      \"method\": \"RNA immunoprecipitation (RIP), shRNA knockdown, qPCR, immunocytochemistry, whole-cell patch clamp electrophysiology in astrocytes\",\n      \"journal\": \"Brain sciences\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — RNA immunoprecipitation demonstrating direct mRNA binding plus functional electrophysiological readout; single lab, multiple methods\",\n      \"pmids\": [\"33440655\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"Spadin, an inhibitor of TREK-1, dramatically reduces astrocytic passive conductance in brain slices. Gene silencing experiments demonstrated that spadin-sensitive currents are mediated specifically by TWIK-1/TREK-1 heterodimeric channels in cultured astrocytes and hippocampal astrocytes from brain slices.\",\n      \"method\": \"Pharmacological inhibition with spadin, shRNA gene silencing of TWIK-1 and TREK-1, whole-cell patch clamp in brain slices and cultured astrocytes\",\n      \"journal\": \"International journal of molecular sciences\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — pharmacological and genetic loss-of-function with electrophysiological readout; single lab\",\n      \"pmids\": [\"33348878\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"KCNK1 siRNA knockdown in IPAH pulmonary arterial smooth muscle cells (PASMCs) suppresses their proliferation and migration, causes membrane depolarization, decreases cytosolic Ca2+, and reduces JNK phosphorylation. Up-regulated KCNK1 in IPAH-PASMCs thus facilitates proliferation/migration via membrane hyperpolarization-dependent Ca2+ signaling and JNK pathway activation.\",\n      \"method\": \"siRNA knockdown, cell proliferation and migration assays, membrane potential measurement, cytosolic Ca2+ imaging, JNK phosphorylation assay in patient-derived PASMCs\",\n      \"journal\": \"Frontiers in cardiovascular medicine\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — siRNA KD in patient-derived cells with multiple defined molecular readouts; single lab\",\n      \"pmids\": [\"38410243\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"TWIK-1-null mice (exon 1 CRISPR-Cas9 KO) exhibit loss of astrocytic background passive K+ conductance and increased susceptibility to kainic acid-induced seizures, establishing that TWIK-1 mediates astrocytic passive conductance and that its loss promotes neuronal hyperexcitability. The previously used exon 2-deleted mice unexpectedly produce a functional internally deleted TWIK-1 protein.\",\n      \"method\": \"CRISPR-Cas9 exon 1 knockout mouse, whole-cell patch clamp of astrocytes, kainic acid seizure susceptibility assay, comparison with exon 2-deleted KO mice\",\n      \"journal\": \"iScience\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — true null KO with electrophysiology and in vivo seizure phenotype, correcting prior incomplete KO models; multiple readouts in one study\",\n      \"pmids\": [\"39811670\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"KCNK1 (TWIK-1) is a two-pore domain, four-transmembrane-segment background K+ channel that forms covalent homodimers via a C69 disulfide bridge and functional heterodimers with TREK-1 (via C69–C93) and TASK-3; it is predominantly retained in intracellular compartments but can be recruited to the plasma membrane by mGluR3/Rab-mediated trafficking, where it mediates astrocytic passive K+ conductance (loss of which increases seizure susceptibility), contributes to resting membrane potential and intrinsic excitability of dentate granule cells, and displays unique selectivity-filter gating that renders it largely silent for K+ under physiological conditions yet capable of conducting inward Na+ leak currents in hypokalemia through a Thr118-dependent mechanism; beyond ion conduction, KCNK1 can non-canonically bind and activate LDHA to drive glycolytic reprogramming, inhibit osteoclastogenesis via suppression of Ca2+ oscillation and JNK-NFATc1 signaling, and is transcriptionally regulated by nuclear receptor CAR and post-transcriptionally stabilized by the RNA-binding protein AEG-1.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"KCNK1 (TWIK-1) is a two-pore-domain, four-transmembrane-segment background K+ channel with a novel architecture that produces time-independent, weakly inward-rectifying currents modulated by PKC and intracellular acidification [#0]. Functional channels assemble as disulfide-linked homodimers through Cys69 in the extracellular M1P1 linker, and this bond is required for channel expression and is detectable as a reducing-agent-sensitive ~81 kDa species in native brain [#1, #2]. The same C69 chemistry allows TWIK-1 to form covalent heterodimers with TREK-1 (C69–C93) and to associate with TASK-3, generating channels with distinct rectification and physiological roles [#4, #7]. A defining feature of TWIK-1 is its low intrinsic activity, which arises from instability of the selectivity-filter gate rather than from intracellular retention or a hydrophobic pore barrier; K+ poorly stabilizes the conductive conformation, whereas Rb+, NH4+, and Cs+ promote a pH-dependent active state [#8]. Under hypokalemia the channel changes selectivity and conducts inward Na+ leak currents through a Thr118-dependent mechanism, driving paradoxical depolarization in cardiomyocytes [#3]. TWIK-1 is predominantly intracellular but is recruited to the plasma membrane by Gi/Go-coupled mGluR3 signaling via Rab-dependent recycling endosome trafficking [#5, #10]. At the astrocyte surface it mediates background passive K+ conductance, and a true null mouse establishes that loss of TWIK-1 abolishes this conductance and increases susceptibility to kainic-acid-induced seizures [#20]; it also shapes resting potential and intrinsic excitability of dentate granule cells [#6]. Beyond ion conduction, KCNK1 non-canonically binds and activates LDHA to drive glycolytic reprogramming and histone lactylation in breast cancer [#16], and modulates Ca2+/JNK signaling to inhibit osteoclastogenesis [#15]. Its expression is controlled transcriptionally by the nuclear receptor CAR [#12] and post-transcriptionally by the RNA-binding protein AEG-1, which stabilizes TWIK-1 mRNA [#17].\",\n  \"teleology\": [\n    {\n      \"year\": 1996,\n      \"claim\": \"Established that KCNK1 defines a new K+ channel class, answering what kind of conductance it produces and how it is gated.\",\n      \"evidence\": \"Heterologous expression in Xenopus oocytes with two-electrode voltage clamp, single-channel recording, and pharmacology\",\n      \"pmids\": [\"8605869\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"No structural basis for inward rectification defined\", \"Native cellular role not yet addressed\"]\n    },\n    {\n      \"year\": 1996,\n      \"claim\": \"Defined the assembly mechanism by showing functional channels require a covalent dimer, answering how subunits oligomerize.\",\n      \"evidence\": \"Biochemical dimerization assay and C69S site-directed mutagenesis with functional expression\",\n      \"pmids\": [\"8978667\", \"9013852\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Whether C69 also mediates heterodimerization not yet tested\", \"Stoichiometry beyond dimer not addressed\"]\n    },\n    {\n      \"year\": 2011,\n      \"claim\": \"Resolved how a 'silent' K+ channel can depolarize cells by demonstrating hypokalemia-induced Na+ permeability through Thr118.\",\n      \"evidence\": \"Patch clamp with T118 mutagenesis plus shRNA knockdown in primary human cardiomyocytes\",\n      \"pmids\": [\"21653227\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Physiological contexts where this leak operates beyond cardiomyocytes unclear\", \"Structural mechanism of selectivity switch not solved\"]\n    },\n    {\n      \"year\": 2012,\n      \"claim\": \"Clarified the source of channel silencing by showing it reflects gating behavior rather than absent surface expression.\",\n      \"evidence\": \"Patch clamp of TWIK-1 in CHO cells under varied extracellular ionic conditions\",\n      \"pmids\": [\"22768960\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Single method, single cell line\", \"Molecular identity of the gate not yet defined\"]\n    },\n    {\n      \"year\": 2013,\n      \"claim\": \"Identified transcriptional and subcellular determinants of KCNK1 abundance and a hepatic phenotype, addressing how the gene is regulated and what it does outside neurons.\",\n      \"evidence\": \"ChIP mapping CAR binding to the Kcnk1 promoter and Kcnk1-/- mouse liver hyperplasia analysis; subcellular fractionation in astrocytes\",\n      \"pmids\": [\"23291559\", \"24368895\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Mechanism linking K+ conductance to hyperplasia suppression unknown\", \"Retention/trafficking machinery not identified in these studies\"]\n    },\n    {\n      \"year\": 2014,\n      \"claim\": \"Showed KCNK1 functions through heterodimerization, establishing a TWIK-1/TREK-1 channel that carries astrocytic passive conductance.\",\n      \"evidence\": \"Reciprocal Co-IP, C69/C93 disulfide mutagenesis, shRNA silencing, and astrocyte electrophysiology with glutamate release assay\",\n      \"pmids\": [\"24496152\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Relative contribution versus homodimers in vivo unresolved\", \"Later genetic studies contested the conductance claim\"]\n    },\n    {\n      \"year\": 2014,\n      \"claim\": \"Extended the channel's role to neuronal excitability by defining its impact on granule cell membrane properties.\",\n      \"evidence\": \"Immunolocalization, shRNA silencing, and patch clamp in hippocampal slices\",\n      \"pmids\": [\"25406588\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Homodimer versus heterodimer identity not resolved here\", \"Knockdown rather than genetic null\"]\n    },\n    {\n      \"year\": 2015,\n      \"claim\": \"Identified a second heterodimer partner and a receptor pathway controlling it, showing TWIK-1/TASK-3 sets granule cell excitability under neurotensin signaling.\",\n      \"evidence\": \"Co-IP, immunohistochemistry, shRNA silencing, and pharmacological NT-NTSR1 activation with patch clamp\",\n      \"pmids\": [\"30416196\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct disulfide linkage with TASK-3 not demonstrated\", \"Single lab\"]\n    },\n    {\n      \"year\": 2015,\n      \"claim\": \"Revealed non-conduction functions of KCNK1 in bone, addressing whether the channel signals beyond K+ flux.\",\n      \"evidence\": \"Gain- and loss-of-function in osteoclast precursors with Ca2+ imaging, JNK, and NFATc1 readouts\",\n      \"pmids\": [\"26208638\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Whether ion conduction is required for osteoclast effect unclear\", \"In vivo bone phenotype not tested\"]\n    },\n    {\n      \"year\": 2015,\n      \"claim\": \"Probed the structural basis of pore dewetting through simulation of lipid and side-chain contributions to hydration.\",\n      \"evidence\": \"Molecular dynamics simulations on the TWIK-1 crystal structure\",\n      \"pmids\": [\"25487004\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"Computational only, no experimental validation\", \"Functional consequence of dewetting not tested in cells\"]\n    },\n    {\n      \"year\": 2015,\n      \"claim\": \"Defined how the intracellular pool reaches the surface, showing mGluR3-driven Rab-dependent trafficking recruits TWIK-1 to the membrane.\",\n      \"evidence\": \"Live-cell imaging of translocation, patch clamp, pharmacological mGluR3 activation, KO controls, and Rab-pathway inhibition\",\n      \"pmids\": [\"26553349\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Specific Rab isoform and adaptors not pinned down\", \"Whether trafficking applies to heterodimers unknown\"]\n    },\n    {\n      \"year\": 2016,\n      \"claim\": \"Provided an in vivo organismal phenotype and rescue, addressing the physiological consequence of KCNK1 loss in the heart.\",\n      \"evidence\": \"Zebrafish morpholino knockdown with WT and dominant-negative human KCNK1 mRNA rescue, oocyte electrophysiology, and localization\",\n      \"pmids\": [\"27103460\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Morpholino off-target effects not fully excluded\", \"Mammalian cardiac requirement not established\"]\n    },\n    {\n      \"year\": 2016,\n      \"claim\": \"Challenged the heterodimer-conductance model by showing genetic deletion of TREK-1 and TWIK-1/TREK-1 leaves astrocyte passive conductance intact.\",\n      \"evidence\": \"TREK-1 single and TWIK-1/TREK-1 double KO mice with in situ astrocyte patch clamp, immunofluorescence, and qRT-PCR\",\n      \"pmids\": [\"26869883\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Discrepancy with knockdown studies unresolved at the time\", \"Possible compensatory channels not excluded\"]\n    },\n    {\n      \"year\": 2019,\n      \"claim\": \"Resolved the mechanism of intrinsic silencing, establishing that selectivity-filter gate instability—not retention or a hydrophobic barrier—limits activity.\",\n      \"evidence\": \"Two-electrode voltage clamp with systematic ion substitution and intracellular K+ variation, testing competing gating hypotheses\",\n      \"pmids\": [\"31806709\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Physiological permeant ion that activates the SF in vivo unclear\", \"Link between SF gating and Na+ leak under hypokalemia not unified\"]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"Reinforced the heterodimer conductance model pharmacologically, showing spadin-sensitive currents are mediated by TWIK-1/TREK-1.\",\n      \"evidence\": \"Spadin inhibition combined with shRNA silencing and patch clamp in slices and cultured astrocytes\",\n      \"pmids\": [\"33348878\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Reconciliation with the negative double-KO result not provided\", \"Spadin specificity for the heterodimer not independently validated\"]\n    },\n    {\n      \"year\": 2021,\n      \"claim\": \"Identified post-transcriptional control of KCNK1, showing AEG-1 stabilizes TWIK-1 mRNA to sustain channel function.\",\n      \"evidence\": \"RNA immunoprecipitation, shRNA knockdown, qPCR, and patch clamp in astrocytes\",\n      \"pmids\": [\"33440655\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Binding site on TWIK-1 mRNA not mapped\", \"Physiological trigger for AEG-1 regulation unknown\"]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Uncovered a moonlighting metabolic function, showing KCNK1 binds and activates LDHA to drive glycolysis and histone lactylation in cancer.\",\n      \"evidence\": \"Co-IP, glycolysis/lactate and histone lactylation assays, knockdown/overexpression, and in vitro/in vivo tumor models\",\n      \"pmids\": [\"38905316\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Whether channel activity contributes to LDHA binding unknown\", \"Structural basis of the KCNK1-LDHA interaction undefined\"]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Extended KCNK1's role to vascular smooth muscle, linking the channel to proliferation via Ca2+ and JNK signaling.\",\n      \"evidence\": \"siRNA knockdown in patient-derived IPAH PASMCs with membrane potential, Ca2+ imaging, and JNK readouts\",\n      \"pmids\": [\"38410243\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Single patient-derived cell system\", \"Causal disease role in IPAH not established in vivo\"]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Provided a definitive genetic test using a true null mouse, establishing that TWIK-1 mediates astrocytic passive conductance and protects against seizures, and correcting flawed prior KO models.\",\n      \"evidence\": \"CRISPR-Cas9 exon 1 knockout mouse with astrocyte patch clamp and kainic acid seizure assay, compared to exon 2-deleted mice\",\n      \"pmids\": [\"39811670\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Homodimer versus heterodimer basis of the conductance not dissected here\", \"Reconciliation with prior negative TREK-1 double-KO not fully addressed\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How the selectivity-filter gating, the hypokalemia Na+ leak, the trafficking control, and the non-canonical LDHA-binding function are integrated into a single physiological logic remains unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No unified structural model linking gate instability to Na+ leak\", \"Whether moonlighting LDHA/osteoclast roles require channel conduction is untested\", \"Mendelian disease association via direct genetic evidence absent from the corpus\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0005215\", \"supporting_discovery_ids\": [0, 2, 3, 8, 11]},\n      {\"term_id\": \"GO:0005216\", \"supporting_discovery_ids\": [0, 2, 8]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005886\", \"supporting_discovery_ids\": [4, 10, 20]},\n      {\"term_id\": \"GO:0005829\", \"supporting_discovery_ids\": [5, 13]},\n      {\"term_id\": \"GO:0005768\", \"supporting_discovery_ids\": [10, 13]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"GO:0034765\", \"supporting_discovery_ids\": [0, 3, 8]},\n      {\"term_id\": \"R-HSA-112316\", \"supporting_discovery_ids\": [6, 7, 20]}\n    ],\n    \"complexes\": [\n      \"TWIK-1/TREK-1 heterodimer\",\n      \"TWIK-1/TASK-3 heterodimer\",\n      \"TWIK-1 homodimer\"\n    ],\n    \"partners\": [\n      \"KCNK2\",\n      \"KCNK9\",\n      \"LDHA\",\n      \"MTDH\",\n      \"NR1I3\"\n    ],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":9,"faith_total":9,"faith_pct":100.0}}