{"gene":"KCNMA1","run_date":"2026-04-28T18:30:27","timeline":{"discoveries":[{"year":1991,"finding":"The Drosophila slowpoke (slo) locus encodes a structural component of Ca2+-activated K+ channels; the predicted polypeptide shares similarity with voltage-activated K+ channel polypeptides in domains essential for function, establishing slo as the founding member of the BK channel gene family.","method":"Genomic and cDNA cloning, sequencing, genetic loss-of-function (slo mutations abolish Ca2+-activated K+ current in muscles and neurons)","journal":"Science","confidence":"High","confidence_rationale":"Tier 1-2 — original cloning with genetic loss-of-function validation; foundational paper with 550 citations","pmids":["1857984"],"is_preprint":false},{"year":1998,"finding":"KCNMA1 (Slo) and Slack co-express to form intermediate-conductance (60–180 pS) calcium-activated K+ channels with distinct pharmacological properties not matching either subunit alone, identifying a heteromeric channel assembly mechanism.","method":"Co-expression in heterologous cells, single-channel patch-clamp electrophysiology","journal":"Nature Neuroscience","confidence":"High","confidence_rationale":"Tier 1 — in vitro reconstitution with single-channel characterization; 145 citations","pmids":["10196543"],"is_preprint":false},{"year":1997,"finding":"A cysteine-rich 59-amino acid alternative splice insert in the C-terminal region of the Slo (KCNMA1) subunit shifts the conductance-voltage curve by −20 to −30 mV when expressed in Xenopus oocytes, demonstrating that alternative splicing directly modulates BK channel voltage dependence.","method":"cDNA cloning, expression in Xenopus oocytes, electrophysiology","journal":"Journal of Biological Chemistry","confidence":"High","confidence_rationale":"Tier 1 — functional reconstitution in oocytes with defined splice construct; 123 citations","pmids":["9115223"],"is_preprint":false},{"year":2005,"finding":"CaMKII phosphorylates Thr107 in the cytosolic S0-S1 loop of BK channel α-subunit (Slo/KCNMA1), progressively increasing channel activity and switching ethanol responses from activation to inhibition, acting as a 'molecular dimmer switch' for alcohol modulation.","method":"Site-directed mutagenesis of Thr107, in vitro CaMKII phosphorylation assay, patch-clamp electrophysiology","journal":"Nature Neuroscience","confidence":"High","confidence_rationale":"Tier 1 — mutagenesis combined with in vitro kinase assay and functional electrophysiology; replicated with multiple phosphorylation states","pmids":["16341213"],"is_preprint":false},{"year":2002,"finding":"The STREX alternative exon of KCNMA1 (Slo) is required for opposing regulation by cAMP- and cGMP-dependent protein kinases; inclusion of the cysteine-rich STREX exon also increases channel sensitivity to inhibition by oxidation 10-fold and increases calcium sensitivity, while these effects depend on co-assembly with β1 subunits and N-terminal variation.","method":"Splice variant expression in cells, electrophysiology, pharmacological modulation, oxidation assays","journal":"Journal of Biological Chemistry","confidence":"High","confidence_rationale":"Tier 1-2 — multiple orthogonal methods (electrophysiology, pharmacology, oxidation) in single study","pmids":["12016222"],"is_preprint":false},{"year":2002,"finding":"Glucocorticoids decrease and adrenal androgens (DHEA, androstenedione, testosterone) increase inclusion of the STREX exon in Slo (KCNMA1) transcripts in bovine chromaffin cells, with glucocorticoid effects blocked by the glucocorticoid receptor antagonist RU38486, demonstrating steroid hormone-regulated alternative splicing of KCNMA1.","method":"Cell culture treatment, RT-PCR quantification of splice variants, pharmacological receptor blockade","journal":"PNAS","confidence":"High","confidence_rationale":"Tier 2 — clean receptor-antagonist blockade confirming steroid-receptor dependence of splicing; 52 citations","pmids":["12032350"],"is_preprint":false},{"year":2013,"finding":"MitoBKCa (mitochondrial BK channel) is encoded by KCNMA1 and a 50-amino acid C-terminal splice insert is essential for its mitochondrial targeting; KCNMA1 knockout mice lack NS1619-mediated cardioprotection, confirming mitoBK functional identity.","method":"Biochemical fractionation of purified mitochondria, Western blotting, electron microscopy, KCNMA1 KO mouse model, pharmacological cardioprotection assay","journal":"PNAS","confidence":"High","confidence_rationale":"Tier 2 — multiple orthogonal methods including KO validation and splice insert functional characterization; 173 citations","pmids":["23754429"],"is_preprint":false},{"year":2013,"finding":"Cav3 (T-type) calcium channels physically associate with KCa1.1 (KCNMA1) at the transmembrane S0 segment of the KCa1.1 N-terminus, enabling low-voltage activation of KCa1.1 current with a 50 mV negative shift in voltage for activation; this Cav3-KCa1.1 complex functions in medial vestibular neurons to contribute to spike repolarization.","method":"Co-immunoprecipitation from tsA-201 cells and rat brain, heterologous co-expression, patch-clamp electrophysiology, pharmacological blockade","journal":"PLoS ONE","confidence":"High","confidence_rationale":"Tier 2 — reciprocal co-IP from brain tissue combined with functional electrophysiology and pharmacology","pmids":["23626738"],"is_preprint":false},{"year":2013,"finding":"TRPV1 and BK (KCNMA1) channels form a functional complex in dorsal root ganglion neurons; Ca2+ influx through TRPV1 activates BK channels within submilliseconds, with local Ca2+ concentration estimated >10 µM, and the interaction is blocked by fast Ca2+ chelator BAPTA but not slow chelator EGTA; the complex was confirmed by co-immunoprecipitation.","method":"Patch-clamp electrophysiology with infrared laser activation, BAPTA/EGTA chelation, fluorescence co-localization, co-immunoprecipitation","journal":"PLoS ONE","confidence":"High","confidence_rationale":"Tier 2 — reciprocal co-IP with functional electrophysiology using fast Ca2+ buffering to demonstrate nanodomain coupling","pmids":["24147119"],"is_preprint":false},{"year":2014,"finding":"EETs (11,12-EET) induce smooth muscle hyperpolarization and vascular relaxation in human internal mammary arteries by targeting a TRPV4-TRPC1-KCa1.1 (KCNMA1) complex; TRPC1 acts as the linker between TRPV4 and KCa1.1α, as demonstrated by physical interaction and functional reconstitution.","method":"Co-immunoprecipitation, HEK293 overexpression reconstitution, microelectrode membrane potential recording, vascular tension assay","journal":"Biochimica et Biophysica Acta","confidence":"High","confidence_rationale":"Tier 2 — reciprocal co-IP combined with functional reconstitution and native tissue validation","pmids":["25511389"],"is_preprint":false},{"year":2012,"finding":"The pore-forming α subunit of KCa1.1 (KCNMA1) co-immunoprecipitates with β1 integrins in rheumatoid arthritis fibroblast-like synoviocytes; blocking KCa1.1 disrupts calcium homeostasis and leads to sustained Akt phosphorylation and talin recruitment to β1 integrins, regulating cell adhesion.","method":"Co-immunoprecipitation, patch-clamp electrophysiology, siRNA knockdown, calcium imaging, Western blotting","journal":"FASEB Journal","confidence":"Medium","confidence_rationale":"Tier 2-3 — co-IP with functional downstream signaling data, single lab","pmids":["28428266"],"is_preprint":false},{"year":2011,"finding":"KCa1.1 (KCNMA1) is the major K+ channel at the plasma membrane of rheumatoid arthritis fibroblast-like synoviocytes; blocking KCa1.1 perturbs calcium homeostasis and inhibits proliferation, VEGF/IL-8/pro-MMP-2 production, and migration/invasion of RA-FLS.","method":"Patch-clamp electrophysiology, siRNA knockdown, pharmacological blockade with iberiotoxin/paxilline, functional invasion/migration assays","journal":"Journal of Biological Chemistry","confidence":"High","confidence_rationale":"Tier 2 — multiple orthogonal methods (electrophysiology, siRNA, pharmacology, functional assays) in defined cellular context","pmids":["22074915"],"is_preprint":false},{"year":2012,"finding":"TMPRSS3 loss-of-function mutation impairs Kcnma1 channel membrane expression at the neck of cochlear inner hair cells, linking TMPRSS3 serine protease activity to proper Kcnma1 surface localization and outward K+ current maturation.","method":"Patch-clamp electrophysiology, proteomic analysis, immunohistochemistry in wild-type vs. Tmprss3 mutant mice","journal":"Human Molecular Genetics","confidence":"Medium","confidence_rationale":"Tier 2 — clean KO/mutant comparison with defined electrophysiological and localization phenotype","pmids":["23255163"],"is_preprint":false},{"year":2005,"finding":"Estrogen decreases STREX exon inclusion in Slo (KCNMA1) transcripts, an effect blocked by estrogen receptor antagonist ICI 182,780; progesterone opposes estrogen's effect; pregnancy progressively reduces STREX transcripts ~80% at term, providing a mechanism for altered PKA regulation of Slo during pregnancy.","method":"RT-PCR quantification of splice variants, estrogen receptor antagonist blockade, pregnancy time-course analysis","journal":"FEBS Letters","confidence":"Medium","confidence_rationale":"Tier 3 — single lab, receptor-antagonist support, mechanistic endpoint established","pmids":["16102753"],"is_preprint":false},{"year":2003,"finding":"The slo core-linker region (not the tail domain) is the critical determinant of differential BK channel responses to ethanol; channels with mslo-type core-linker are consistently activated by ethanol while channels with bslo-type core-linker show inhibition, refractoriness, or activation.","method":"Chimeric channel construction (core-tail domain swaps between mslo and bslo), single-channel patch-clamp in cell-free membrane patches","journal":"Alcoholism: Clinical and Experimental Research","confidence":"High","confidence_rationale":"Tier 1 — chimeric domain-swap reconstitution with single-channel recording clearly assigns structural determinant","pmids":["14574235"],"is_preprint":false},{"year":2008,"finding":"Aldosterone stimulates colonic K+ secretion exclusively via luminal KCa1.1 (KCNMA1) BK channels in mouse distal colon; high K+ diet increases BK α- and β2-subunit mRNA and promotes luminal membrane expression of BK channels; effect is absent in BK α-subunit knockout mice.","method":"Ussing chamber short-circuit current measurement, iberiotoxin pharmacological blockade, BK α-subunit KO mice, immunohistochemistry, semi-quantitative RT-PCR","journal":"Journal of Physiology","confidence":"High","confidence_rationale":"Tier 2 — genetic KO validation combined with pharmacology and expression data in native tissue","pmids":["18617563"],"is_preprint":false},{"year":2012,"finding":"Aldosterone induces active K+ secretion in rat distal colon by transcriptionally upregulating both Kcnma1 and Kcnn4c channel expression at the mucosal membrane; actinomycin D (RNA synthesis inhibitor) prevents the aldosterone-induced mRNA increase, demonstrating transcriptional regulation.","method":"Ussing chamber 86Rb flux measurements, iberiotoxin/TRAM-34 pharmacological dissection, Western blotting, quantitative RT-PCR, actinomycin D blockade","journal":"American Journal of Physiology – Cell Physiology","confidence":"High","confidence_rationale":"Tier 2 — pharmacological dissection, transcriptional inhibitor, and protein expression all concordant","pmids":["22322970"],"is_preprint":false},{"year":2008,"finding":"KCa1.1 (KCNMA1) channels localize to the apical membranes of striated and excretory duct cells (but not granular duct cells) in the mouse submandibular gland; genetic null mutation of KCa1.1 abolishes K+ secretion and eliminates its flow-rate dependence, demonstrating KCa1.1 as the primary K+ secretory pathway in salivary gland ducts.","method":"KCa1.1 null mice, ionic flux measurement, paxilline pharmacological blockade, immunohistochemistry for subcellular localization","journal":"American Journal of Physiology – Cell Physiology","confidence":"High","confidence_rationale":"Tier 2 — genetic KO with defined transport phenotype plus localization data","pmids":["18216162"],"is_preprint":false},{"year":2012,"finding":"In vascular smooth muscle cells (VSMCs), BKα (KCNMA1) subunit mobility on the plasma membrane is strongly restricted by co-association with β1 auxiliary subunit (~50% reduction in diffusion), cytoskeletal actin, and direct interaction with caveolin-1 (Cav1), as shown by FRET; disrupting actin with cytochalasin D increases BKα mobility.","method":"Single-molecule TIRF microscopy, FRAP, FRET analysis, cytochalasin D/jasplakinolide actin manipulation","journal":"American Journal of Physiology – Cell Physiology","confidence":"High","confidence_rationale":"Tier 1-2 — single-molecule live imaging with FRET structural validation and pharmacological perturbation","pmids":["22301058"],"is_preprint":false},{"year":2014,"finding":"Electrophysiological recordings from KCNMA1 knockout cardiomyocyte mitoplasts confirm paxilline- and NS11021-sensitive BK currents of 190 pS conductance present in wild-type but absent in BK−/− cells; BK−/− hearts show increased post-anoxic ROS production and impaired ischemic preconditioning protection, demonstrating mitoBK regulates mitochondrial oxidative state and cardioprotection.","method":"Mitoplast patch-clamp electrophysiology, KCNMA1 KO mice, ex vivo ischemia-reperfusion model, ROS measurement, oxidative phosphorylation capacity","journal":"PLoS ONE","confidence":"High","confidence_rationale":"Tier 2 — genetic KO electrophysiology combined with functional cardiac protection and ROS assays","pmids":["25072914"],"is_preprint":false},{"year":2020,"finding":"Nrf2 directly transcriptionally regulates KCNMA1 expression by binding to antioxidant response elements (AREs) in the KCNMA1 promoter; Nrf2 KO mice show reduced BK-α mRNA and protein, decreased BK current density in coronary arterial smooth muscle cells, and adenoviral Nrf2 expression or pharmacological Nrf2 activation rescues BK channel expression and activity.","method":"Nrf2 KO mice, promoter-luciferase reporter assay, adenoviral Nrf2 overexpression, patch-clamp electrophysiology, RT-PCR, Western blotting","journal":"Journal of Molecular and Cellular Cardiology","confidence":"High","confidence_rationale":"Tier 2 — promoter-luciferase directly demonstrates Nrf2-ARE binding; KO plus overexpression confirm functional consequence","pmids":["32147517"],"is_preprint":false},{"year":2016,"finding":"Loss of plasma membrane expression of KCa1.1 α-subunit (KCNMA1) occurs in myotonic dystrophy type 1 (DM1) myoblasts; inhibiting KCa1.1 in healthy myoblasts elevates cytosolic calcium and alters NFκB levels, increases proliferation, and impairs migration and myotube fusion—phenotypes matching DM1; re-introducing functional KCa1.1 α-subunits into DM1 myoblasts normalizes proliferation and rescues Mef2 expression.","method":"siRNA knockdown, pharmacological blockade, overexpression in DM1 myoblasts, calcium imaging, functional proliferation/migration/fusion assays, Western blotting","journal":"Cell Death & Disease","confidence":"High","confidence_rationale":"Tier 2 — gain- and loss-of-function with defined mechanistic readouts (calcium, NFκB, Mef2) in disease-relevant cells","pmids":["27763639"],"is_preprint":false},{"year":2004,"finding":"In Drosophila, slo (KCNMA1 ortholog) K+ channel gene expression is induced by ethanol sedation in the nervous system and mediates rapid drug tolerance; a slo loss-of-function mutation prevents tolerance acquisition, while transgenic induction of slo in naive animals phenocopies tolerance.","method":"Drosophila genetic loss-of-function mutation, inducible transgene expression, behavioral ethanol tolerance assays","journal":"PNAS","confidence":"High","confidence_rationale":"Tier 2 — bidirectional genetic manipulation (LOF and GOF) with defined behavioral phenotype","pmids":["15569939"],"is_preprint":false},{"year":2019,"finding":"KCNMA1 gain-of-function mutations (D434G, N999S) shift BK channel activation to negative potentials with faster activation and slower deactivation, while loss-of-function mutations (e.g., Gly375Arg, Gly356Arg, Ser351Tyr) abolish or reduce BK current and shift activation curves toward positive potentials; these properties are established as the mechanistic basis of KCNMA1-linked channelopathy.","method":"Patch-clamp electrophysiology of mutant channels expressed in HEK cells, exome/genome sequencing","journal":"Human Molecular Genetics","confidence":"High","confidence_rationale":"Tier 1-2 — direct electrophysiological characterization of multiple disease mutations with clear gain/loss-of-function classification","pmids":["31152168"],"is_preprint":false},{"year":2022,"finding":"The KCNMA1-N999S mutation produces stronger BK channel gain-of-function than D434G, with greater negative shift in V1/2, faster activation, and slower deactivation; Kcnma1N999S/WT mice show increased BK currents, increased action potential firing, decreased seizure threshold, and paroxysmal dyskinesia; the double mutation N999S/R1128W shows no additional functional change over N999S alone; acetazolamide has no direct modulatory action on BK channels.","method":"Patch-clamp electrophysiology in HEK293T cells and transgenic mice, seizure threshold testing, in vivo behavioral paroxysmal dyskinesia assay, action potential voltage commands","journal":"eLife","confidence":"High","confidence_rationale":"Tier 2 — multiple patient alleles compared in heterologous cells and knock-in mouse models with orthogonal behavioral and electrophysiological endpoints","pmids":["35819138"],"is_preprint":false},{"year":2010,"finding":"β4 subunit increases KCa1.1 (Slo/KCNMA1) responsiveness to Ca2+ at physiological hair cell operating voltages (around −50 mV); β4 and β1 together reduce surface expression of Slo in chick cochlear hair cells; β4-mediated Ca2+ sensitivity increase is associated with its role in electrical frequency tuning in low-frequency hair cells.","method":"Cloning of chick β4 and β1 subunits, heterologous expression, patch-clamp electrophysiology, surface expression quantification","journal":"American Journal of Physiology – Cell Physiology","confidence":"Medium","confidence_rationale":"Tier 2 — functional reconstitution with defined subunit combinations, single lab","pmids":["21178105"],"is_preprint":false},{"year":2006,"finding":"KCNMA1 gene amplification at chromosomal region 10q22 drives BK channel protein overexpression and increased BK currents in PC-3 prostate cancer cells; specific blockade of BK channels by iberiotoxin or KCNMA1 RNAi significantly inhibits K+ currents and cell proliferation.","method":"FISH for gene amplification, siRNA knockdown, iberiotoxin pharmacological blockade, whole-cell patch-clamp, proliferation assays","journal":"Oncogene","confidence":"Medium","confidence_rationale":"Tier 2 — siRNA and pharmacological blockade with electrophysiological and proliferation readouts; single lab","pmids":["17146446"],"is_preprint":false},{"year":2016,"finding":"The β3b regulatory subunit of KCa1.1 (KCNMA1) is expressed by highly invasive CD44high RA fibroblast-like synoviocytes; siRNA silencing of β3 (but not β1) reduces KCa1.1 channel density at the plasma membrane and inhibits RA-FLS invasiveness, identifying β3b-containing KCa1.1 as a disease-relevant channel complex.","method":"siRNA knockdown of β subunits, patch-clamp electrophysiology, flow cytometric sorting by CD44 expression, invasion assays","journal":"Arthritis Research & Therapy","confidence":"Medium","confidence_rationale":"Tier 2-3 — siRNA with electrophysiology and functional invasion data; single lab but multiple readouts","pmids":["27165430"],"is_preprint":false},{"year":2004,"finding":"In Aplysia bag cell neurons, a PKA-regulated Slo-a splice isoform (containing a PKA consensus phosphorylation site) is expressed in adult but not juvenile neurons; PKA reduces open probability of Slo-a but not Slo-b; this developmental switch in splice isoform expression allows mature neurons to generate afterdischarges required for reproduction.","method":"cDNA library cloning, heterologous expression in CHO cells, patch-clamp electrophysiology, PKA catalytic subunit application, immunocytochemistry in adult vs. juvenile neurons","journal":"Journal of Biological Chemistry","confidence":"High","confidence_rationale":"Tier 2 — PKA functional assay on two isoforms combined with developmental immunocytochemistry confirming in vivo relevance","pmids":["15375169"],"is_preprint":false}],"current_model":"KCNMA1 encodes the pore-forming α subunit of the large-conductance Ca2+- and voltage-activated BK K+ channel, which is activated by membrane depolarization and intracellular Ca2+ (supplied by functionally coupled Ca2+ channels including Cav1, Cav3, and TRPV1 in nanodomain complexes); channel properties are extensively tuned by alternative splicing (notably the STREX exon, which inverts PKA regulation and is itself regulated by steroid hormones and pregnancy), post-translational phosphorylation (CaMKII phosphorylation of Thr107 shifts ethanol sensitivity), and auxiliary β subunits (β1–β4 modulate Ca2+ sensitivity, kinetics, and surface expression); the channel localizes to the plasma membrane of excitable and epithelial cells and to the mitochondrial inner membrane (via a specific C-terminal splice insert) where it modulates ROS production and ischemic preconditioning; KCNMA1 transcription is directly regulated by Nrf2 binding to ARE elements in the promoter; gain-of-function mutations shift activation to hyperpolarized potentials causing dyskinesia and epilepsy, while loss-of-function mutations reduce or abolish BK current causing neurodevelopmental syndromes."},"narrative":{"teleology":[{"year":1991,"claim":"Cloning of Drosophila slowpoke established a new gene family encoding Ca²⁺-activated K⁺ channels structurally related to voltage-gated K⁺ channels, resolving the molecular identity of BK channels.","evidence":"Genomic/cDNA cloning and genetic loss-of-function in Drosophila muscles and neurons","pmids":["1857984"],"confidence":"High","gaps":["Mammalian ortholog not yet cloned","Mechanism of Ca²⁺ sensing unknown","Subunit stoichiometry undetermined"]},{"year":1997,"claim":"Discovery that a cysteine-rich C-terminal splice insert shifts voltage dependence by −20 to −30 mV established alternative splicing as a direct mechanism for tuning BK channel gating.","evidence":"Expression of defined splice constructs in Xenopus oocytes with electrophysiology","pmids":["9115223"],"confidence":"High","gaps":["Number and functional impact of other splice sites unknown","In vivo relevance of this particular insert not tested"]},{"year":1998,"claim":"Co-expression of KCNMA1 with Slack demonstrated that BK α subunits can form heteromeric channels with distinct conductance and pharmacology, expanding the functional repertoire beyond homomeric assemblies.","evidence":"Heterologous co-expression with single-channel patch-clamp","pmids":["10196543"],"confidence":"High","gaps":["Stoichiometry and structure of heteromeric complex unknown","In vivo prevalence of Slo/Slack heteromers not established"]},{"year":2002,"claim":"The STREX exon was shown to be required for opposing regulation by cAMP/cGMP kinases and to increase oxidation and Ca²⁺ sensitivity, while steroid hormones (glucocorticoids vs. androgens) regulate STREX inclusion, establishing hormone-controlled alternative splicing as a major regulatory axis of BK channel function.","evidence":"Splice variant electrophysiology, pharmacological modulation, RT-PCR with receptor antagonist blockade in chromaffin cells","pmids":["12016222","12032350"],"confidence":"High","gaps":["Splicing trans-factors mediating steroid effects not identified","Structural basis of STREX-dependent PKA regulation unknown"]},{"year":2004,"claim":"Bidirectional genetic manipulation of slo in Drosophila proved that BK channel expression is both induced by ethanol and necessary/sufficient for rapid alcohol tolerance, while Aplysia studies showed developmental splicing switches PKA regulation—together establishing BK channels as key mediators of neural adaptation.","evidence":"Drosophila LOF/GOF behavioral assays; Aplysia splice isoform electrophysiology with PKA application","pmids":["15569939","15375169"],"confidence":"High","gaps":["Mammalian in vivo ethanol tolerance role not directly tested","Signal controlling developmental splice switching unknown"]},{"year":2005,"claim":"Identification of CaMKII phosphorylation at Thr107 as a molecular switch that progressively increases BK activity and converts ethanol responses from activation to inhibition resolved how post-translational modification tunes pharmacological sensitivity at a single residue.","evidence":"Site-directed mutagenesis, in vitro CaMKII phosphorylation, patch-clamp electrophysiology","pmids":["16341213"],"confidence":"High","gaps":["In vivo phosphorylation state at Thr107 under ethanol exposure not measured","Interplay with STREX-dependent PKA regulation unclear"]},{"year":2005,"claim":"Estrogen and progesterone were shown to oppositely regulate STREX inclusion, with pregnancy progressively eliminating ~80% of STREX transcripts, providing a mechanism for altered BK channel regulation during gestation.","evidence":"RT-PCR with estrogen receptor antagonist blockade and pregnancy time-course analysis","pmids":["16102753"],"confidence":"Medium","gaps":["Single lab finding; independent replication not documented","Downstream functional consequence on uterine BK current not directly measured"]},{"year":2008,"claim":"Genetic knockout studies demonstrated that KCNMA1 is the primary K⁺ secretory channel in colonic and salivary duct epithelia, with aldosterone transcriptionally upregulating its expression, establishing the channel's essential role in epithelial ion transport.","evidence":"BK α-subunit KO mice, Ussing chamber flux measurements, iberiotoxin/paxilline pharmacology, actinomycin D transcription block","pmids":["18617563","18216162","22322970"],"confidence":"High","gaps":["Aldosterone-responsive transcription factors binding KCNMA1 promoter not identified at this time","Contribution of specific β subunits to epithelial targeting incompletely defined"]},{"year":2012,"claim":"Single-molecule imaging in vascular smooth muscle revealed that BKα membrane dynamics are restricted by β1 subunit co-association, actin cytoskeleton, and direct caveolin-1 interaction, establishing a framework for how the channel is spatially organized in signaling microdomains.","evidence":"Single-molecule TIRF, FRAP, FRET, cytochalasin D perturbation in VSMCs","pmids":["22301058"],"confidence":"High","gaps":["Structural basis of caveolin-1 interaction not resolved","Whether caveolar localization is required for functional coupling to Ca²⁺ sources unknown"]},{"year":2013,"claim":"Physical nanodomain coupling of KCNMA1 with Cav3 (via the S0 segment), TRPV1, and subsequently TRPV4/TRPC1 was demonstrated, showing that local Ca²⁺ microdomains from diverse sources activate BK channels within submilliseconds to control neuronal spike repolarization and vascular tone.","evidence":"Reciprocal co-IP from brain tissue and cell lines, BAPTA vs. EGTA chelation kinetics, patch-clamp electrophysiology, vascular tension assays","pmids":["23626738","24147119","25511389"],"confidence":"High","gaps":["Atomic-resolution structure of BK–Cav3 or BK–TRPV1 complex unavailable","Relative in vivo prevalence of different Ca²⁺ source complexes across tissues unknown"]},{"year":2013,"claim":"A 50-amino acid C-terminal splice insert was identified as necessary and sufficient for mitochondrial targeting of BK channels; KCNMA1 KO mice lacked mitoBK current and cardioprotection, definitively assigning the mitochondrial BK channel to the KCNMA1 gene.","evidence":"Mitochondrial fractionation, electron microscopy, mitoplast patch-clamp, KCNMA1 KO mice, ischemia-reperfusion and ROS assays","pmids":["23754429","25072914"],"confidence":"High","gaps":["Mechanism of mitoBK import into inner membrane not resolved","Physiological Ca²⁺ source activating mitoBK in the matrix unknown"]},{"year":2019,"claim":"Systematic electrophysiological characterization of KCNMA1 disease mutations established that gain-of-function alleles (D434G, N999S) shift activation negatively causing dyskinesia/epilepsy while loss-of-function alleles abolish current causing neurodevelopmental syndromes, defining KCNMA1-linked channelopathy as a bidirectional spectrum.","evidence":"Patch-clamp of mutant channels in HEK cells, exome sequencing of patients, knock-in mouse models with seizure threshold and dyskinesia assays","pmids":["31152168","35819138"],"confidence":"High","gaps":["Cell-type-specific consequences of mutations in native neurons not fully characterized","No genotype-targeted therapy validated"]},{"year":2020,"claim":"Nrf2 was identified as a direct transcriptional activator of KCNMA1 via ARE elements in the promoter, linking antioxidant signaling to BK channel expression in coronary arteries and providing a transcriptional mechanism for oxidative-stress-dependent channel regulation.","evidence":"Nrf2 KO mice, promoter-luciferase reporter, adenoviral rescue, patch-clamp in coronary smooth muscle","pmids":["32147517"],"confidence":"High","gaps":["Whether Nrf2 regulation generalizes beyond vascular smooth muscle not tested","Other transcription factors acting on KCNMA1 promoter not comprehensively mapped"]},{"year":null,"claim":"Key open questions include the structural basis of BK channel coupling to its diverse Ca²⁺ source partners, the mechanisms governing splice-insert-directed mitochondrial import, comprehensive mapping of transcription factor inputs to the KCNMA1 promoter across tissues, and development of mutation-specific therapeutic strategies for KCNMA1 channelopathies.","evidence":"","pmids":[],"confidence":"Low","gaps":["No high-resolution structure of BK in complex with any Ca²⁺ channel partner","Mitochondrial import pathway for mitoBK splice variant unknown","No genotype-targeted pharmacotherapy validated for KCNMA1 channelopathy"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0005215","term_label":"transporter activity","supporting_discovery_ids":[0,1,2,15,17,19,23]},{"term_id":"GO:0140299","term_label":"molecular sensor activity","supporting_discovery_ids":[3,14,22]}],"localization":[{"term_id":"GO:0005886","term_label":"plasma membrane","supporting_discovery_ids":[2,11,12,15,17,18,21,26]},{"term_id":"GO:0005739","term_label":"mitochondrion","supporting_discovery_ids":[6,19]}],"pathway":[{"term_id":"R-HSA-112316","term_label":"Neuronal System","supporting_discovery_ids":[3,7,8,22,23,24]},{"term_id":"R-HSA-162582","term_label":"Signal Transduction","supporting_discovery_ids":[9,20,21]},{"term_id":"R-HSA-1643685","term_label":"Disease","supporting_discovery_ids":[23,24]}],"complexes":["BK channel (α4 homotetramer or α4β4 complex)","Cav3–BK nanodomain complex","TRPV1–BK nanodomain complex","TRPV4–TRPC1–BK complex"],"partners":["KCNT1","CACNA1G","TRPV1","TRPV4","TRPC1","KCNMB1","KCNMB4","CAV1"],"other_free_text":[]},"mechanistic_narrative":"KCNMA1 encodes the pore-forming α subunit of the large-conductance calcium- and voltage-activated potassium (BK) channel, a ubiquitous regulator of membrane excitability, epithelial ion secretion, and mitochondrial oxidative stress responses. The channel is activated by membrane depolarization and intracellular Ca²⁺ supplied through nanodomain coupling with voltage-gated (Cav3) and TRP-family (TRPV1, TRPV4/TRPC1) calcium channels [PMID:23626738, PMID:24147119, PMID:25511389]; its biophysical properties are extensively tuned by alternative splicing—notably the STREX exon, which inverts PKA regulation and is itself controlled by steroid hormones and pregnancy [PMID:12016222, PMID:12032350, PMID:16102753]—by CaMKII phosphorylation of Thr107 that switches ethanol sensitivity [PMID:16341213], by auxiliary β subunits that modulate Ca²⁺ sensitivity, kinetics, and surface trafficking [PMID:21178105, PMID:27165430], and by Nrf2-dependent transcription through ARE elements in the promoter [PMID:32147517]. A C-terminal splice insert targets the channel to the mitochondrial inner membrane where it limits reactive oxygen species production and mediates ischemic preconditioning cardioprotection [PMID:23754429, PMID:25072914]. Gain-of-function mutations (D434G, N999S) that shift activation to hyperpolarized potentials cause paroxysmal dyskinesia and epilepsy, while loss-of-function mutations that abolish or reduce BK current cause neurodevelopmental channelopathy [PMID:31152168, PMID:35819138]."},"prefetch_data":{"uniprot":{"accession":"Q12791","full_name":"Calcium-activated potassium channel subunit alpha-1","aliases":["BK channel","BKCA alpha","Calcium-activated potassium channel, subfamily M subunit alpha-1","K(VCA)alpha","KCa1.1","Maxi K channel","MaxiK","Slo-alpha","Slo1","Slowpoke homolog","Slo homolog","hSlo"],"length_aa":1236,"mass_kda":137.6,"function":"Potassium channel activated by both membrane depolarization or increase in cytosolic Ca(2+) that mediates export of K(+) (PubMed:14523450, PubMed:29330545, PubMed:31152168). It is also activated by the concentration of cytosolic Mg(2+). Its activation dampens the excitatory events that elevate the cytosolic Ca(2+) concentration and/or depolarize the cell membrane. It therefore contributes to repolarization of the membrane potential. Plays a key role in controlling excitability in a number of systems, such as regulation of the contraction of smooth muscle, the tuning of hair cells in the cochlea, regulation of transmitter release, and innate immunity. In smooth muscles, its activation by high level of Ca(2+), caused by ryanodine receptors in the sarcoplasmic reticulum, regulates the membrane potential. In cochlea cells, its number and kinetic properties partly determine the characteristic frequency of each hair cell and thereby helps to establish a tonotopic map. Kinetics of KCNMA1 channels are determined by alternative splicing, phosphorylation status and its combination with modulating beta subunits. Highly sensitive to both iberiotoxin (IbTx) and charybdotoxin (CTX). Possibly induces sleep when activated by melatonin and through melatonin receptor MTNR1A-dependent dissociation of G-beta and G-gamma subunits, leading to increased sensitivity to Ca(2+) and reduced synaptic transmission (PubMed:32958651) Potassium channel activated by both membrane depolarization or increase in cytosolic Ca(2+) that mediates export of K(+)","subcellular_location":"Cell membrane","url":"https://www.uniprot.org/uniprotkb/Q12791/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/KCNMA1","classification":"Not Classified","n_dependent_lines":1,"n_total_lines":1208,"dependency_fraction":0.0008278145695364238},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/KCNMA1","total_profiled":1310},"omim":[{"mim_id":"618729","title":"LIANG-WANG SYNDROME; LIWAS","url":"https://www.omim.org/entry/618729"},{"mim_id":"618596","title":"EPILEPSY, IDIOPATHIC GENERALIZED, SUSCEPTIBILITY TO, 16; EIG16","url":"https://www.omim.org/entry/618596"},{"mim_id":"617643","title":"CEREBELLAR ATROPHY, DEVELOPMENTAL DELAY, AND SEIZURES; CADEDS","url":"https://www.omim.org/entry/617643"},{"mim_id":"615215","title":"POTASSIUM CHANNEL, SUBFAMILY U, MEMBER 1; KCNU1","url":"https://www.omim.org/entry/615215"},{"mim_id":"613505","title":"LEUCINE-RICH REPEAT-CONTAINING PROTEIN 26; LRRC26","url":"https://www.omim.org/entry/613505"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"","locations":[],"tissue_specificity":"Low tissue specificity","tissue_distribution":"Detected in many","driving_tissues":[],"url":"https://www.proteinatlas.org/search/KCNMA1"},"hgnc":{"alias_symbol":["KCa1.1","mSLO1"],"prev_symbol":["SLO"]},"alphafold":{"accession":"Q12791","domains":[{"cath_id":"-","chopping":"160-386","consensus_level":"medium","plddt":91.1198,"start":160,"end":386},{"cath_id":"3.30.70","chopping":"1099-1182","consensus_level":"medium","plddt":89.5504,"start":1099,"end":1182}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q12791","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q12791-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q12791-F1-predicted_aligned_error_v6.png","plddt_mean":76.0},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=KCNMA1","jax_strain_url":"https://www.jax.org/strain/search?query=KCNMA1"},"sequence":{"accession":"Q12791","fasta_url":"https://rest.uniprot.org/uniprotkb/Q12791.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q12791/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q12791"}},"corpus_meta":[{"pmid":"1857984","id":"PMC_1857984","title":"A component of calcium-activated potassium channels encoded by the Drosophila slo locus.","date":"1991","source":"Science (New York, N.Y.)","url":"https://pubmed.ncbi.nlm.nih.gov/1857984","citation_count":550,"is_preprint":false},{"pmid":"17115074","id":"PMC_17115074","title":"High-conductance potassium channels of the SLO family.","date":"2006","source":"Nature reviews. 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the predicted polypeptide shares similarity with voltage-activated K+ channel polypeptides in domains essential for function, establishing slo as the founding member of the BK channel gene family.\",\n      \"method\": \"Genomic and cDNA cloning, sequencing, genetic loss-of-function (slo mutations abolish Ca2+-activated K+ current in muscles and neurons)\",\n      \"journal\": \"Science\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 — original cloning with genetic loss-of-function validation; foundational paper with 550 citations\",\n      \"pmids\": [\"1857984\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1998,\n      \"finding\": \"KCNMA1 (Slo) and Slack co-express to form intermediate-conductance (60–180 pS) calcium-activated K+ channels with distinct pharmacological properties not matching either subunit alone, identifying a heteromeric channel assembly mechanism.\",\n      \"method\": \"Co-expression in heterologous cells, single-channel patch-clamp electrophysiology\",\n      \"journal\": \"Nature Neuroscience\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 — in vitro reconstitution with single-channel characterization; 145 citations\",\n      \"pmids\": [\"10196543\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1997,\n      \"finding\": \"A cysteine-rich 59-amino acid alternative splice insert in the C-terminal region of the Slo (KCNMA1) subunit shifts the conductance-voltage curve by −20 to −30 mV when expressed in Xenopus oocytes, demonstrating that alternative splicing directly modulates BK channel voltage dependence.\",\n      \"method\": \"cDNA cloning, expression in Xenopus oocytes, electrophysiology\",\n      \"journal\": \"Journal of Biological Chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 — functional reconstitution in oocytes with defined splice construct; 123 citations\",\n      \"pmids\": [\"9115223\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2005,\n      \"finding\": \"CaMKII phosphorylates Thr107 in the cytosolic S0-S1 loop of BK channel α-subunit (Slo/KCNMA1), progressively increasing channel activity and switching ethanol responses from activation to inhibition, acting as a 'molecular dimmer switch' for alcohol modulation.\",\n      \"method\": \"Site-directed mutagenesis of Thr107, in vitro CaMKII phosphorylation assay, patch-clamp electrophysiology\",\n      \"journal\": \"Nature Neuroscience\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 — mutagenesis combined with in vitro kinase assay and functional electrophysiology; replicated with multiple phosphorylation states\",\n      \"pmids\": [\"16341213\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2002,\n      \"finding\": \"The STREX alternative exon of KCNMA1 (Slo) is required for opposing regulation by cAMP- and cGMP-dependent protein kinases; inclusion of the cysteine-rich STREX exon also increases channel sensitivity to inhibition by oxidation 10-fold and increases calcium sensitivity, while these effects depend on co-assembly with β1 subunits and N-terminal variation.\",\n      \"method\": \"Splice variant expression in cells, electrophysiology, pharmacological modulation, oxidation assays\",\n      \"journal\": \"Journal of Biological Chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 — multiple orthogonal methods (electrophysiology, pharmacology, oxidation) in single study\",\n      \"pmids\": [\"12016222\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2002,\n      \"finding\": \"Glucocorticoids decrease and adrenal androgens (DHEA, androstenedione, testosterone) increase inclusion of the STREX exon in Slo (KCNMA1) transcripts in bovine chromaffin cells, with glucocorticoid effects blocked by the glucocorticoid receptor antagonist RU38486, demonstrating steroid hormone-regulated alternative splicing of KCNMA1.\",\n      \"method\": \"Cell culture treatment, RT-PCR quantification of splice variants, pharmacological receptor blockade\",\n      \"journal\": \"PNAS\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — clean receptor-antagonist blockade confirming steroid-receptor dependence of splicing; 52 citations\",\n      \"pmids\": [\"12032350\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"MitoBKCa (mitochondrial BK channel) is encoded by KCNMA1 and a 50-amino acid C-terminal splice insert is essential for its mitochondrial targeting; KCNMA1 knockout mice lack NS1619-mediated cardioprotection, confirming mitoBK functional identity.\",\n      \"method\": \"Biochemical fractionation of purified mitochondria, Western blotting, electron microscopy, KCNMA1 KO mouse model, pharmacological cardioprotection assay\",\n      \"journal\": \"PNAS\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — multiple orthogonal methods including KO validation and splice insert functional characterization; 173 citations\",\n      \"pmids\": [\"23754429\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"Cav3 (T-type) calcium channels physically associate with KCa1.1 (KCNMA1) at the transmembrane S0 segment of the KCa1.1 N-terminus, enabling low-voltage activation of KCa1.1 current with a 50 mV negative shift in voltage for activation; this Cav3-KCa1.1 complex functions in medial vestibular neurons to contribute to spike repolarization.\",\n      \"method\": \"Co-immunoprecipitation from tsA-201 cells and rat brain, heterologous co-expression, patch-clamp electrophysiology, pharmacological blockade\",\n      \"journal\": \"PLoS ONE\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — reciprocal co-IP from brain tissue combined with functional electrophysiology and pharmacology\",\n      \"pmids\": [\"23626738\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"TRPV1 and BK (KCNMA1) channels form a functional complex in dorsal root ganglion neurons; Ca2+ influx through TRPV1 activates BK channels within submilliseconds, with local Ca2+ concentration estimated >10 µM, and the interaction is blocked by fast Ca2+ chelator BAPTA but not slow chelator EGTA; the complex was confirmed by co-immunoprecipitation.\",\n      \"method\": \"Patch-clamp electrophysiology with infrared laser activation, BAPTA/EGTA chelation, fluorescence co-localization, co-immunoprecipitation\",\n      \"journal\": \"PLoS ONE\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — reciprocal co-IP with functional electrophysiology using fast Ca2+ buffering to demonstrate nanodomain coupling\",\n      \"pmids\": [\"24147119\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"EETs (11,12-EET) induce smooth muscle hyperpolarization and vascular relaxation in human internal mammary arteries by targeting a TRPV4-TRPC1-KCa1.1 (KCNMA1) complex; TRPC1 acts as the linker between TRPV4 and KCa1.1α, as demonstrated by physical interaction and functional reconstitution.\",\n      \"method\": \"Co-immunoprecipitation, HEK293 overexpression reconstitution, microelectrode membrane potential recording, vascular tension assay\",\n      \"journal\": \"Biochimica et Biophysica Acta\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — reciprocal co-IP combined with functional reconstitution and native tissue validation\",\n      \"pmids\": [\"25511389\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"The pore-forming α subunit of KCa1.1 (KCNMA1) co-immunoprecipitates with β1 integrins in rheumatoid arthritis fibroblast-like synoviocytes; blocking KCa1.1 disrupts calcium homeostasis and leads to sustained Akt phosphorylation and talin recruitment to β1 integrins, regulating cell adhesion.\",\n      \"method\": \"Co-immunoprecipitation, patch-clamp electrophysiology, siRNA knockdown, calcium imaging, Western blotting\",\n      \"journal\": \"FASEB Journal\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2-3 — co-IP with functional downstream signaling data, single lab\",\n      \"pmids\": [\"28428266\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2011,\n      \"finding\": \"KCa1.1 (KCNMA1) is the major K+ channel at the plasma membrane of rheumatoid arthritis fibroblast-like synoviocytes; blocking KCa1.1 perturbs calcium homeostasis and inhibits proliferation, VEGF/IL-8/pro-MMP-2 production, and migration/invasion of RA-FLS.\",\n      \"method\": \"Patch-clamp electrophysiology, siRNA knockdown, pharmacological blockade with iberiotoxin/paxilline, functional invasion/migration assays\",\n      \"journal\": \"Journal of Biological Chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — multiple orthogonal methods (electrophysiology, siRNA, pharmacology, functional assays) in defined cellular context\",\n      \"pmids\": [\"22074915\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"TMPRSS3 loss-of-function mutation impairs Kcnma1 channel membrane expression at the neck of cochlear inner hair cells, linking TMPRSS3 serine protease activity to proper Kcnma1 surface localization and outward K+ current maturation.\",\n      \"method\": \"Patch-clamp electrophysiology, proteomic analysis, immunohistochemistry in wild-type vs. Tmprss3 mutant mice\",\n      \"journal\": \"Human Molecular Genetics\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — clean KO/mutant comparison with defined electrophysiological and localization phenotype\",\n      \"pmids\": [\"23255163\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2005,\n      \"finding\": \"Estrogen decreases STREX exon inclusion in Slo (KCNMA1) transcripts, an effect blocked by estrogen receptor antagonist ICI 182,780; progesterone opposes estrogen's effect; pregnancy progressively reduces STREX transcripts ~80% at term, providing a mechanism for altered PKA regulation of Slo during pregnancy.\",\n      \"method\": \"RT-PCR quantification of splice variants, estrogen receptor antagonist blockade, pregnancy time-course analysis\",\n      \"journal\": \"FEBS Letters\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 — single lab, receptor-antagonist support, mechanistic endpoint established\",\n      \"pmids\": [\"16102753\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2003,\n      \"finding\": \"The slo core-linker region (not the tail domain) is the critical determinant of differential BK channel responses to ethanol; channels with mslo-type core-linker are consistently activated by ethanol while channels with bslo-type core-linker show inhibition, refractoriness, or activation.\",\n      \"method\": \"Chimeric channel construction (core-tail domain swaps between mslo and bslo), single-channel patch-clamp in cell-free membrane patches\",\n      \"journal\": \"Alcoholism: Clinical and Experimental Research\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 — chimeric domain-swap reconstitution with single-channel recording clearly assigns structural determinant\",\n      \"pmids\": [\"14574235\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2008,\n      \"finding\": \"Aldosterone stimulates colonic K+ secretion exclusively via luminal KCa1.1 (KCNMA1) BK channels in mouse distal colon; high K+ diet increases BK α- and β2-subunit mRNA and promotes luminal membrane expression of BK channels; effect is absent in BK α-subunit knockout mice.\",\n      \"method\": \"Ussing chamber short-circuit current measurement, iberiotoxin pharmacological blockade, BK α-subunit KO mice, immunohistochemistry, semi-quantitative RT-PCR\",\n      \"journal\": \"Journal of Physiology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — genetic KO validation combined with pharmacology and expression data in native tissue\",\n      \"pmids\": [\"18617563\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"Aldosterone induces active K+ secretion in rat distal colon by transcriptionally upregulating both Kcnma1 and Kcnn4c channel expression at the mucosal membrane; actinomycin D (RNA synthesis inhibitor) prevents the aldosterone-induced mRNA increase, demonstrating transcriptional regulation.\",\n      \"method\": \"Ussing chamber 86Rb flux measurements, iberiotoxin/TRAM-34 pharmacological dissection, Western blotting, quantitative RT-PCR, actinomycin D blockade\",\n      \"journal\": \"American Journal of Physiology – Cell Physiology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — pharmacological dissection, transcriptional inhibitor, and protein expression all concordant\",\n      \"pmids\": [\"22322970\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2008,\n      \"finding\": \"KCa1.1 (KCNMA1) channels localize to the apical membranes of striated and excretory duct cells (but not granular duct cells) in the mouse submandibular gland; genetic null mutation of KCa1.1 abolishes K+ secretion and eliminates its flow-rate dependence, demonstrating KCa1.1 as the primary K+ secretory pathway in salivary gland ducts.\",\n      \"method\": \"KCa1.1 null mice, ionic flux measurement, paxilline pharmacological blockade, immunohistochemistry for subcellular localization\",\n      \"journal\": \"American Journal of Physiology – Cell Physiology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — genetic KO with defined transport phenotype plus localization data\",\n      \"pmids\": [\"18216162\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"In vascular smooth muscle cells (VSMCs), BKα (KCNMA1) subunit mobility on the plasma membrane is strongly restricted by co-association with β1 auxiliary subunit (~50% reduction in diffusion), cytoskeletal actin, and direct interaction with caveolin-1 (Cav1), as shown by FRET; disrupting actin with cytochalasin D increases BKα mobility.\",\n      \"method\": \"Single-molecule TIRF microscopy, FRAP, FRET analysis, cytochalasin D/jasplakinolide actin manipulation\",\n      \"journal\": \"American Journal of Physiology – Cell Physiology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 — single-molecule live imaging with FRET structural validation and pharmacological perturbation\",\n      \"pmids\": [\"22301058\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"Electrophysiological recordings from KCNMA1 knockout cardiomyocyte mitoplasts confirm paxilline- and NS11021-sensitive BK currents of 190 pS conductance present in wild-type but absent in BK−/− cells; BK−/− hearts show increased post-anoxic ROS production and impaired ischemic preconditioning protection, demonstrating mitoBK regulates mitochondrial oxidative state and cardioprotection.\",\n      \"method\": \"Mitoplast patch-clamp electrophysiology, KCNMA1 KO mice, ex vivo ischemia-reperfusion model, ROS measurement, oxidative phosphorylation capacity\",\n      \"journal\": \"PLoS ONE\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — genetic KO electrophysiology combined with functional cardiac protection and ROS assays\",\n      \"pmids\": [\"25072914\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"Nrf2 directly transcriptionally regulates KCNMA1 expression by binding to antioxidant response elements (AREs) in the KCNMA1 promoter; Nrf2 KO mice show reduced BK-α mRNA and protein, decreased BK current density in coronary arterial smooth muscle cells, and adenoviral Nrf2 expression or pharmacological Nrf2 activation rescues BK channel expression and activity.\",\n      \"method\": \"Nrf2 KO mice, promoter-luciferase reporter assay, adenoviral Nrf2 overexpression, patch-clamp electrophysiology, RT-PCR, Western blotting\",\n      \"journal\": \"Journal of Molecular and Cellular Cardiology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — promoter-luciferase directly demonstrates Nrf2-ARE binding; KO plus overexpression confirm functional consequence\",\n      \"pmids\": [\"32147517\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"Loss of plasma membrane expression of KCa1.1 α-subunit (KCNMA1) occurs in myotonic dystrophy type 1 (DM1) myoblasts; inhibiting KCa1.1 in healthy myoblasts elevates cytosolic calcium and alters NFκB levels, increases proliferation, and impairs migration and myotube fusion—phenotypes matching DM1; re-introducing functional KCa1.1 α-subunits into DM1 myoblasts normalizes proliferation and rescues Mef2 expression.\",\n      \"method\": \"siRNA knockdown, pharmacological blockade, overexpression in DM1 myoblasts, calcium imaging, functional proliferation/migration/fusion assays, Western blotting\",\n      \"journal\": \"Cell Death & Disease\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — gain- and loss-of-function with defined mechanistic readouts (calcium, NFκB, Mef2) in disease-relevant cells\",\n      \"pmids\": [\"27763639\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2004,\n      \"finding\": \"In Drosophila, slo (KCNMA1 ortholog) K+ channel gene expression is induced by ethanol sedation in the nervous system and mediates rapid drug tolerance; a slo loss-of-function mutation prevents tolerance acquisition, while transgenic induction of slo in naive animals phenocopies tolerance.\",\n      \"method\": \"Drosophila genetic loss-of-function mutation, inducible transgene expression, behavioral ethanol tolerance assays\",\n      \"journal\": \"PNAS\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — bidirectional genetic manipulation (LOF and GOF) with defined behavioral phenotype\",\n      \"pmids\": [\"15569939\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"KCNMA1 gain-of-function mutations (D434G, N999S) shift BK channel activation to negative potentials with faster activation and slower deactivation, while loss-of-function mutations (e.g., Gly375Arg, Gly356Arg, Ser351Tyr) abolish or reduce BK current and shift activation curves toward positive potentials; these properties are established as the mechanistic basis of KCNMA1-linked channelopathy.\",\n      \"method\": \"Patch-clamp electrophysiology of mutant channels expressed in HEK cells, exome/genome sequencing\",\n      \"journal\": \"Human Molecular Genetics\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 — direct electrophysiological characterization of multiple disease mutations with clear gain/loss-of-function classification\",\n      \"pmids\": [\"31152168\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"The KCNMA1-N999S mutation produces stronger BK channel gain-of-function than D434G, with greater negative shift in V1/2, faster activation, and slower deactivation; Kcnma1N999S/WT mice show increased BK currents, increased action potential firing, decreased seizure threshold, and paroxysmal dyskinesia; the double mutation N999S/R1128W shows no additional functional change over N999S alone; acetazolamide has no direct modulatory action on BK channels.\",\n      \"method\": \"Patch-clamp electrophysiology in HEK293T cells and transgenic mice, seizure threshold testing, in vivo behavioral paroxysmal dyskinesia assay, action potential voltage commands\",\n      \"journal\": \"eLife\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — multiple patient alleles compared in heterologous cells and knock-in mouse models with orthogonal behavioral and electrophysiological endpoints\",\n      \"pmids\": [\"35819138\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2010,\n      \"finding\": \"β4 subunit increases KCa1.1 (Slo/KCNMA1) responsiveness to Ca2+ at physiological hair cell operating voltages (around −50 mV); β4 and β1 together reduce surface expression of Slo in chick cochlear hair cells; β4-mediated Ca2+ sensitivity increase is associated with its role in electrical frequency tuning in low-frequency hair cells.\",\n      \"method\": \"Cloning of chick β4 and β1 subunits, heterologous expression, patch-clamp electrophysiology, surface expression quantification\",\n      \"journal\": \"American Journal of Physiology – Cell Physiology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — functional reconstitution with defined subunit combinations, single lab\",\n      \"pmids\": [\"21178105\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2006,\n      \"finding\": \"KCNMA1 gene amplification at chromosomal region 10q22 drives BK channel protein overexpression and increased BK currents in PC-3 prostate cancer cells; specific blockade of BK channels by iberiotoxin or KCNMA1 RNAi significantly inhibits K+ currents and cell proliferation.\",\n      \"method\": \"FISH for gene amplification, siRNA knockdown, iberiotoxin pharmacological blockade, whole-cell patch-clamp, proliferation assays\",\n      \"journal\": \"Oncogene\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — siRNA and pharmacological blockade with electrophysiological and proliferation readouts; single lab\",\n      \"pmids\": [\"17146446\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"The β3b regulatory subunit of KCa1.1 (KCNMA1) is expressed by highly invasive CD44high RA fibroblast-like synoviocytes; siRNA silencing of β3 (but not β1) reduces KCa1.1 channel density at the plasma membrane and inhibits RA-FLS invasiveness, identifying β3b-containing KCa1.1 as a disease-relevant channel complex.\",\n      \"method\": \"siRNA knockdown of β subunits, patch-clamp electrophysiology, flow cytometric sorting by CD44 expression, invasion assays\",\n      \"journal\": \"Arthritis Research & Therapy\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2-3 — siRNA with electrophysiology and functional invasion data; single lab but multiple readouts\",\n      \"pmids\": [\"27165430\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2004,\n      \"finding\": \"In Aplysia bag cell neurons, a PKA-regulated Slo-a splice isoform (containing a PKA consensus phosphorylation site) is expressed in adult but not juvenile neurons; PKA reduces open probability of Slo-a but not Slo-b; this developmental switch in splice isoform expression allows mature neurons to generate afterdischarges required for reproduction.\",\n      \"method\": \"cDNA library cloning, heterologous expression in CHO cells, patch-clamp electrophysiology, PKA catalytic subunit application, immunocytochemistry in adult vs. juvenile neurons\",\n      \"journal\": \"Journal of Biological Chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — PKA functional assay on two isoforms combined with developmental immunocytochemistry confirming in vivo relevance\",\n      \"pmids\": [\"15375169\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"KCNMA1 encodes the pore-forming α subunit of the large-conductance Ca2+- and voltage-activated BK K+ channel, which is activated by membrane depolarization and intracellular Ca2+ (supplied by functionally coupled Ca2+ channels including Cav1, Cav3, and TRPV1 in nanodomain complexes); channel properties are extensively tuned by alternative splicing (notably the STREX exon, which inverts PKA regulation and is itself regulated by steroid hormones and pregnancy), post-translational phosphorylation (CaMKII phosphorylation of Thr107 shifts ethanol sensitivity), and auxiliary β subunits (β1–β4 modulate Ca2+ sensitivity, kinetics, and surface expression); the channel localizes to the plasma membrane of excitable and epithelial cells and to the mitochondrial inner membrane (via a specific C-terminal splice insert) where it modulates ROS production and ischemic preconditioning; KCNMA1 transcription is directly regulated by Nrf2 binding to ARE elements in the promoter; gain-of-function mutations shift activation to hyperpolarized potentials causing dyskinesia and epilepsy, while loss-of-function mutations reduce or abolish BK current causing neurodevelopmental syndromes.\"\n}\n```","stage2_raw":"```json\n{\n  \"mechanistic_narrative\": \"KCNMA1 encodes the pore-forming α subunit of the large-conductance calcium- and voltage-activated potassium (BK) channel, a ubiquitous regulator of membrane excitability, epithelial ion secretion, and mitochondrial oxidative stress responses. The channel is activated by membrane depolarization and intracellular Ca²⁺ supplied through nanodomain coupling with voltage-gated (Cav3) and TRP-family (TRPV1, TRPV4/TRPC1) calcium channels [PMID:23626738, PMID:24147119, PMID:25511389]; its biophysical properties are extensively tuned by alternative splicing—notably the STREX exon, which inverts PKA regulation and is itself controlled by steroid hormones and pregnancy [PMID:12016222, PMID:12032350, PMID:16102753]—by CaMKII phosphorylation of Thr107 that switches ethanol sensitivity [PMID:16341213], by auxiliary β subunits that modulate Ca²⁺ sensitivity, kinetics, and surface trafficking [PMID:21178105, PMID:27165430], and by Nrf2-dependent transcription through ARE elements in the promoter [PMID:32147517]. A C-terminal splice insert targets the channel to the mitochondrial inner membrane where it limits reactive oxygen species production and mediates ischemic preconditioning cardioprotection [PMID:23754429, PMID:25072914]. Gain-of-function mutations (D434G, N999S) that shift activation to hyperpolarized potentials cause paroxysmal dyskinesia and epilepsy, while loss-of-function mutations that abolish or reduce BK current cause neurodevelopmental channelopathy [PMID:31152168, PMID:35819138].\",\n  \"teleology\": [\n    {\n      \"year\": 1991,\n      \"claim\": \"Cloning of Drosophila slowpoke established a new gene family encoding Ca²⁺-activated K⁺ channels structurally related to voltage-gated K⁺ channels, resolving the molecular identity of BK channels.\",\n      \"evidence\": \"Genomic/cDNA cloning and genetic loss-of-function in Drosophila muscles and neurons\",\n      \"pmids\": [\"1857984\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Mammalian ortholog not yet cloned\", \"Mechanism of Ca²⁺ sensing unknown\", \"Subunit stoichiometry undetermined\"]\n    },\n    {\n      \"year\": 1997,\n      \"claim\": \"Discovery that a cysteine-rich C-terminal splice insert shifts voltage dependence by −20 to −30 mV established alternative splicing as a direct mechanism for tuning BK channel gating.\",\n      \"evidence\": \"Expression of defined splice constructs in Xenopus oocytes with electrophysiology\",\n      \"pmids\": [\"9115223\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Number and functional impact of other splice sites unknown\", \"In vivo relevance of this particular insert not tested\"]\n    },\n    {\n      \"year\": 1998,\n      \"claim\": \"Co-expression of KCNMA1 with Slack demonstrated that BK α subunits can form heteromeric channels with distinct conductance and pharmacology, expanding the functional repertoire beyond homomeric assemblies.\",\n      \"evidence\": \"Heterologous co-expression with single-channel patch-clamp\",\n      \"pmids\": [\"10196543\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Stoichiometry and structure of heteromeric complex unknown\", \"In vivo prevalence of Slo/Slack heteromers not established\"]\n    },\n    {\n      \"year\": 2002,\n      \"claim\": \"The STREX exon was shown to be required for opposing regulation by cAMP/cGMP kinases and to increase oxidation and Ca²⁺ sensitivity, while steroid hormones (glucocorticoids vs. androgens) regulate STREX inclusion, establishing hormone-controlled alternative splicing as a major regulatory axis of BK channel function.\",\n      \"evidence\": \"Splice variant electrophysiology, pharmacological modulation, RT-PCR with receptor antagonist blockade in chromaffin cells\",\n      \"pmids\": [\"12016222\", \"12032350\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Splicing trans-factors mediating steroid effects not identified\", \"Structural basis of STREX-dependent PKA regulation unknown\"]\n    },\n    {\n      \"year\": 2004,\n      \"claim\": \"Bidirectional genetic manipulation of slo in Drosophila proved that BK channel expression is both induced by ethanol and necessary/sufficient for rapid alcohol tolerance, while Aplysia studies showed developmental splicing switches PKA regulation—together establishing BK channels as key mediators of neural adaptation.\",\n      \"evidence\": \"Drosophila LOF/GOF behavioral assays; Aplysia splice isoform electrophysiology with PKA application\",\n      \"pmids\": [\"15569939\", \"15375169\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Mammalian in vivo ethanol tolerance role not directly tested\", \"Signal controlling developmental splice switching unknown\"]\n    },\n    {\n      \"year\": 2005,\n      \"claim\": \"Identification of CaMKII phosphorylation at Thr107 as a molecular switch that progressively increases BK activity and converts ethanol responses from activation to inhibition resolved how post-translational modification tunes pharmacological sensitivity at a single residue.\",\n      \"evidence\": \"Site-directed mutagenesis, in vitro CaMKII phosphorylation, patch-clamp electrophysiology\",\n      \"pmids\": [\"16341213\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"In vivo phosphorylation state at Thr107 under ethanol exposure not measured\", \"Interplay with STREX-dependent PKA regulation unclear\"]\n    },\n    {\n      \"year\": 2005,\n      \"claim\": \"Estrogen and progesterone were shown to oppositely regulate STREX inclusion, with pregnancy progressively eliminating ~80% of STREX transcripts, providing a mechanism for altered BK channel regulation during gestation.\",\n      \"evidence\": \"RT-PCR with estrogen receptor antagonist blockade and pregnancy time-course analysis\",\n      \"pmids\": [\"16102753\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Single lab finding; independent replication not documented\", \"Downstream functional consequence on uterine BK current not directly measured\"]\n    },\n    {\n      \"year\": 2008,\n      \"claim\": \"Genetic knockout studies demonstrated that KCNMA1 is the primary K⁺ secretory channel in colonic and salivary duct epithelia, with aldosterone transcriptionally upregulating its expression, establishing the channel's essential role in epithelial ion transport.\",\n      \"evidence\": \"BK α-subunit KO mice, Ussing chamber flux measurements, iberiotoxin/paxilline pharmacology, actinomycin D transcription block\",\n      \"pmids\": [\"18617563\", \"18216162\", \"22322970\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Aldosterone-responsive transcription factors binding KCNMA1 promoter not identified at this time\", \"Contribution of specific β subunits to epithelial targeting incompletely defined\"]\n    },\n    {\n      \"year\": 2012,\n      \"claim\": \"Single-molecule imaging in vascular smooth muscle revealed that BKα membrane dynamics are restricted by β1 subunit co-association, actin cytoskeleton, and direct caveolin-1 interaction, establishing a framework for how the channel is spatially organized in signaling microdomains.\",\n      \"evidence\": \"Single-molecule TIRF, FRAP, FRET, cytochalasin D perturbation in VSMCs\",\n      \"pmids\": [\"22301058\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Structural basis of caveolin-1 interaction not resolved\", \"Whether caveolar localization is required for functional coupling to Ca²⁺ sources unknown\"]\n    },\n    {\n      \"year\": 2013,\n      \"claim\": \"Physical nanodomain coupling of KCNMA1 with Cav3 (via the S0 segment), TRPV1, and subsequently TRPV4/TRPC1 was demonstrated, showing that local Ca²⁺ microdomains from diverse sources activate BK channels within submilliseconds to control neuronal spike repolarization and vascular tone.\",\n      \"evidence\": \"Reciprocal co-IP from brain tissue and cell lines, BAPTA vs. EGTA chelation kinetics, patch-clamp electrophysiology, vascular tension assays\",\n      \"pmids\": [\"23626738\", \"24147119\", \"25511389\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Atomic-resolution structure of BK–Cav3 or BK–TRPV1 complex unavailable\", \"Relative in vivo prevalence of different Ca²⁺ source complexes across tissues unknown\"]\n    },\n    {\n      \"year\": 2013,\n      \"claim\": \"A 50-amino acid C-terminal splice insert was identified as necessary and sufficient for mitochondrial targeting of BK channels; KCNMA1 KO mice lacked mitoBK current and cardioprotection, definitively assigning the mitochondrial BK channel to the KCNMA1 gene.\",\n      \"evidence\": \"Mitochondrial fractionation, electron microscopy, mitoplast patch-clamp, KCNMA1 KO mice, ischemia-reperfusion and ROS assays\",\n      \"pmids\": [\"23754429\", \"25072914\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Mechanism of mitoBK import into inner membrane not resolved\", \"Physiological Ca²⁺ source activating mitoBK in the matrix unknown\"]\n    },\n    {\n      \"year\": 2019,\n      \"claim\": \"Systematic electrophysiological characterization of KCNMA1 disease mutations established that gain-of-function alleles (D434G, N999S) shift activation negatively causing dyskinesia/epilepsy while loss-of-function alleles abolish current causing neurodevelopmental syndromes, defining KCNMA1-linked channelopathy as a bidirectional spectrum.\",\n      \"evidence\": \"Patch-clamp of mutant channels in HEK cells, exome sequencing of patients, knock-in mouse models with seizure threshold and dyskinesia assays\",\n      \"pmids\": [\"31152168\", \"35819138\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Cell-type-specific consequences of mutations in native neurons not fully characterized\", \"No genotype-targeted therapy validated\"]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"Nrf2 was identified as a direct transcriptional activator of KCNMA1 via ARE elements in the promoter, linking antioxidant signaling to BK channel expression in coronary arteries and providing a transcriptional mechanism for oxidative-stress-dependent channel regulation.\",\n      \"evidence\": \"Nrf2 KO mice, promoter-luciferase reporter, adenoviral rescue, patch-clamp in coronary smooth muscle\",\n      \"pmids\": [\"32147517\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Whether Nrf2 regulation generalizes beyond vascular smooth muscle not tested\", \"Other transcription factors acting on KCNMA1 promoter not comprehensively mapped\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"Key open questions include the structural basis of BK channel coupling to its diverse Ca²⁺ source partners, the mechanisms governing splice-insert-directed mitochondrial import, comprehensive mapping of transcription factor inputs to the KCNMA1 promoter across tissues, and development of mutation-specific therapeutic strategies for KCNMA1 channelopathies.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"No high-resolution structure of BK in complex with any Ca²⁺ channel partner\", \"Mitochondrial import pathway for mitoBK splice variant unknown\", \"No genotype-targeted pharmacotherapy validated for KCNMA1 channelopathy\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0005215\", \"supporting_discovery_ids\": [0, 1, 2, 15, 17, 19, 23]},\n      {\"term_id\": \"GO:0140299\", \"supporting_discovery_ids\": [3, 14, 22]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005886\", \"supporting_discovery_ids\": [2, 11, 12, 15, 17, 18, 21, 26]},\n      {\"term_id\": \"GO:0005739\", \"supporting_discovery_ids\": [6, 19]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"GO:0382551\", \"supporting_discovery_ids\": [0, 1, 2, 15, 17]},\n      {\"term_id\": \"R-HSA-112316\", \"supporting_discovery_ids\": [3, 7, 8, 22, 23, 24]},\n      {\"term_id\": \"R-HSA-162582\", \"supporting_discovery_ids\": [9, 20, 21]},\n      {\"term_id\": \"R-HSA-1643685\", \"supporting_discovery_ids\": [23, 24]}\n    ],\n    \"complexes\": [\n      \"BK channel (α4 homotetramer or α4β4 complex)\",\n      \"Cav3–BK nanodomain complex\",\n      \"TRPV1–BK nanodomain complex\",\n      \"TRPV4–TRPC1–BK complex\"\n    ],\n    \"partners\": [\n      \"KCNT1\",\n      \"CACNA1G\",\n      \"TRPV1\",\n      \"TRPV4\",\n      \"TRPC1\",\n      \"KCNMB1\",\n      \"KCNMB4\",\n      \"CAV1\"\n    ],\n    \"other_free_text\": []\n  }\n}\n```"}