{"gene":"CHRNA1","run_date":"2026-04-28T17:28:52","timeline":{"discoveries":[{"year":2007,"finding":"IRF8 binds the CHRNA1 promoter and drives its transcription in thymic epithelial cells; a promoter variant prevents IRF8 binding and abrogates CHRNA1 promoter activity. AIRE also transactivates CHRNA1 in medullary thymic epithelial cells, and together IRF8 and AIRE regulate promiscuous CHRNA1 expression to set the threshold for self-tolerance.","method":"Promoter re-sequencing, in vitro transcription/binding assays (IRF8–promoter interaction), transactivation assay in thymic epithelial cells, ex vivo mRNA quantification from human medullary thymic epithelial cells","journal":"Nature","confidence":"High","confidence_rationale":"Tier 2 — multiple orthogonal methods (binding assay, transactivation, ex vivo), replicated across two independent human populations","pmids":["17687331"],"is_preprint":false},{"year":2008,"finding":"hnRNP H binds an intronic splicing silencer (ISS) near the 3' end of CHRNA1 intron 3 and promotes skipping of the non-functional exon P3A; a congenital myasthenic syndrome mutation (IVS3-8G>A) disrupts the ISS, reduces hnRNP H affinity ~100-fold, and causes exclusive inclusion of exon P3A, producing a non-functional acetylcholine receptor α-subunit.","method":"Patient mutation identification, in vitro binding/affinity assays (ISS–hnRNP H), siRNA knockdown of hnRNP H, hnRNP H tethering assay, minigene splicing reporter","journal":"Human molecular genetics","confidence":"High","confidence_rationale":"Tier 1–2 — reconstitution of splicing mechanism, mutagenesis, siRNA, and tethering assay in a single study","pmids":["18806275"],"is_preprint":false},{"year":2009,"finding":"Polypyrimidine tract binding protein (PTB) binds near the 3' end of CHRNA1 intron 3 and induces skipping of exon P3A; tannic acid increases PTB expression and ameliorates aberrant exon P3A inclusion caused by the IVS3-8G>A mutation without altering hnRNP H levels.","method":"PTB deletion/binding assays, PTB promoter deletion analysis, compound screen (960 bioactive compounds), tannic acid dose–response for PTB expression","journal":"Human molecular genetics","confidence":"Medium","confidence_rationale":"Tier 2 — functional binding and promoter assays in single lab with chemical validation","pmids":["19147685"],"is_preprint":false},{"year":2013,"finding":"hnRNP L binds hnRNP L-binding sites in CHRNA1 pre-mRNA and interacts with PTB through its proline-rich region, promoting PTB binding to the polypyrimidine tract upstream of exon P3A; this inhibits U2AF65 and U1 snRNP association, blocking exon P3A definition and thus promoting exon skipping. hnRNP LL, which lacks the proline-rich region, cannot bind PTB and instead promotes exon P3A inclusion — the two proteins antagonistically modulate PTB-mediated splicing suppression.","method":"Co-immunoprecipitation (hnRNP L–PTB interaction), siRNA knockdown, minigene splicing assays, patient mutation analysis, RNA pulldown","journal":"Scientific reports","confidence":"High","confidence_rationale":"Tier 2 — reciprocal Co-IP, siRNA, and minigene reporter with mechanistic epistasis in a single study","pmids":["24121633"],"is_preprint":false},{"year":2012,"finding":"Agrin stimulation induces co-localization of Chrna1 mRNA with assembled nicotinic acetylcholine receptor (AChR) at postsynaptic clusters in C2C12 myotubes; Stau1 protein interacts with Chrna1 mRNA, and Stau1 knockdown causes defective AChR clustering, implicating mRNA localization in neuromuscular junction formation.","method":"RT-PCR of AChR affinity-column and ultracentrifugation fractions, RNA immunoprecipitation (Stau1–Chrna1 mRNA), RNAi knockdown of Stau1, AChR clustering assay","journal":"FEBS letters","confidence":"Medium","confidence_rationale":"Tier 2–3 — pulldown and functional knockdown in single lab with defined cellular phenotype","pmids":["22884571"],"is_preprint":false},{"year":2022,"finding":"AAV9-mediated overexpression of CHRNA1 in hindlimb muscle decreases neuromuscular junction innervation percentage and reduces skeletal muscle mass (gastrocnemius mass index and fiber cross-sectional area), compound muscle action potential, and contractility, demonstrating that elevated CHRNA1 drives sarcopenia-like muscle denervation and atrophy.","method":"AAV9-CHRNA1 local injection in mouse hindlimb, immunofluorescence for innervation, electrophysiology (compound muscle action potential), muscle mass/fiber morphometry","journal":"Experimental gerontology","confidence":"Medium","confidence_rationale":"Tier 2 — in vivo gain-of-function with multiple orthogonal readouts in single study","pmids":["35809807"],"is_preprint":false},{"year":2021,"finding":"CHRNA1 upregulation in sweat glands promotes excessive sweat secretion; siRNA-mediated CHRNA1 silencing decreases sweat secretion, reduces sweat secretory granules, lowers serum acetylcholine, and downregulates AQP5 and CACNA1C in sweat glands, as well as BDNF and NRG-1 in sympathetic ganglia axons.","method":"siRNA knockdown in pilocarpine-induced hyperhidrosis mouse model, transmission electron microscopy, ELISA, immunohistochemistry, Western blot, qRT-PCR","journal":"Molecular and cellular neurosciences","confidence":"Medium","confidence_rationale":"Tier 2 — loss-of-function with multiple molecular readouts in in vivo model, single lab","pmids":["33476802"],"is_preprint":false},{"year":2022,"finding":"Cisatracurium, an antagonist of CHRNA1, blocks the CHRNA1 ion channel (without altering CHRNA1 gene or protein expression) and alleviates hyperhidrosis in mice; overexpression of CHRNA1 abolishes cisatracurium's effect while CHRNA1 knockdown prevents additional benefit, establishing that cisatracurium acts specifically through CHRNA1 channel blockade.","method":"HEK293 cell expression of Chrna1, cisatracurium treatment in vivo (hyperhidrosis mouse model), CHRNA1 overexpression/siRNA epistasis experiments, sweat secretion quantification, Western blot","journal":"Annals of clinical and translational neurology","confidence":"Medium","confidence_rationale":"Tier 2 — pharmacological channel blockade validated by genetic epistasis (OE and KD) in single lab","pmids":["35393764"],"is_preprint":false},{"year":2023,"finding":"PAI1 (SERPINE1) negatively regulates CHRNA1 expression in sweat glands; Serpine1 knockout increases Chrna1 expression and hyperhidrosis markers (ACH, CACNA1C, AQP5), while Serpine1 transgenic overexpression reduces them. CHRNA1-expressing AAV rescues hyperhidrosis in Serpine1-Tg mice, and CHRNA1 antagonist cisatracurium reverses the Pai1-KO hyperhidrosis phenotype, placing PAI1 upstream of CHRNA1 in this pathway.","method":"Serpine1 KO and Tg mice, pilocarpine hyperhidrosis model, Chrna1-expressing AAV rescue, cisatracurium antagonism, ELISA, RT-PCR, Western blot","journal":"Orphanet journal of rare diseases","confidence":"Medium","confidence_rationale":"Tier 2 — genetic epistasis across KO, Tg, and AAV rescue with pharmacological corroboration in single lab","pmids":["37542348"],"is_preprint":false},{"year":2022,"finding":"The CHRNA1 variant c.257G>A (p.Arg86His) causes inclusion of the alternatively-spliced evolutionary exon P3A, producing a non-functional AChR α-subunit that leads to AChR-deficiency congenital myasthenic syndrome with a distinctive phenotype of facial and distal weakness.","method":"Whole-exome sequencing of 13 patients from nine kindreds, clinical phenotyping, molecular characterization of P3A inclusion","journal":"Neuromuscular disorders : NMD","confidence":"Medium","confidence_rationale":"Tier 3 — genotype–phenotype correlation across multiple families; functional mechanism of P3A inclusion inferred from prior mechanistic studies","pmids":["36634413"],"is_preprint":false},{"year":2025,"finding":"circAtxn10 acts as a sponge for miR-143-3p through direct binding; miR-143-3p directly targets three binding sites in the Chrna1 3'-UTR to suppress its expression. Chrna1 knockdown impairs myogenesis, while Chrna1 overexpression dramatically enhances myogenic marker expression and myotube formation, establishing a circAtxn10–miR-143-3p–Chrna1 regulatory axis in skeletal muscle differentiation.","method":"RNA pulldown/luciferase reporter for circAtxn10–miR-143-3p interaction, 3'-UTR luciferase reporter for miR-143-3p–Chrna1 targeting, miR-143-3p mimic, siRNA knockdown and overexpression of Chrna1, myogenic differentiation assays","journal":"The Korean journal of physiology & pharmacology","confidence":"Medium","confidence_rationale":"Tier 2 — direct RNA interaction validation plus loss- and gain-of-function with defined myogenic phenotype in single lab","pmids":["40701844"],"is_preprint":false}],"current_model":"CHRNA1 encodes the muscle nicotinic acetylcholine receptor α1-subunit, an ion channel subunit whose expression and splicing are mechanistically regulated by IRF8/AIRE at the promoter level, and by hnRNP H, PTB, hnRNP L, hnRNP LL, and a circAtxn10–miR-143-3p axis at the pre-mRNA splicing/localization level; the alternatively-spliced exon P3A produces a non-functional subunit whose inclusion is suppressed by hnRNP H and PTB in normal muscle, and CHRNA1 protein at the neuromuscular junction is required for proper AChR clustering, muscle innervation, and myogenic differentiation, while its upregulation drives sarcopenia-like denervation and pathological sweat secretion through a PAI1-regulated pathway."},"narrative":{"teleology":[{"year":2007,"claim":"How CHRNA1 is transcribed outside muscle was unknown; discovery that IRF8 and AIRE directly transactivate the CHRNA1 promoter in thymic epithelial cells established the mechanism for promiscuous thymic expression underlying central tolerance to AChR.","evidence":"Promoter sequencing, IRF8–DNA binding assays, transactivation assays, and ex vivo mRNA quantification in human medullary thymic epithelial cells","pmids":["17687331"],"confidence":"High","gaps":["Whether IRF8/AIRE regulation extends to other AChR subunit genes","Mechanism linking reduced thymic CHRNA1 expression to autoimmune myasthenia gravis susceptibility"]},{"year":2008,"claim":"The mechanism enforcing skipping of the non-functional exon P3A was undefined; identification of hnRNP H binding to an intronic splicing silencer in intron 3, and demonstration that a patient mutation (IVS3-8G>A) abolishes this binding to cause constitutive P3A inclusion, established the first cis-regulatory element and trans-acting factor controlling CHRNA1 alternative splicing.","evidence":"Patient mutation identification, in vitro binding/affinity measurements, siRNA knockdown, hnRNP H tethering assay, minigene splicing reporter","pmids":["18806275"],"confidence":"High","gaps":["Structural basis of hnRNP H–ISS recognition","Whether additional splicing factors cooperate with hnRNP H at this element"]},{"year":2009,"claim":"Whether other splicing regulators independently control P3A skipping was unclear; PTB was shown to bind near intron 3 and suppress P3A inclusion, and tannic acid was identified as a PTB inducer that ameliorates aberrant splicing caused by the IVS3-8G>A mutation.","evidence":"PTB binding/deletion assays, promoter analysis, bioactive compound screen, tannic acid dose–response","pmids":["19147685"],"confidence":"Medium","gaps":["In vivo efficacy of tannic acid for CMS","Whether PTB and hnRNP H act independently or cooperatively at intron 3"]},{"year":2012,"claim":"How CHRNA1 mRNA is positioned at the neuromuscular synapse was unknown; Stau1 was shown to bind Chrna1 mRNA and mediate its co-localization with AChR clusters upon agrin stimulation, linking mRNA transport to postsynaptic differentiation.","evidence":"RNA immunoprecipitation (Stau1–Chrna1 mRNA), RNAi knockdown, AChR clustering assay in C2C12 myotubes","pmids":["22884571"],"confidence":"Medium","gaps":["Cis-element in Chrna1 mRNA recognized by Stau1","Whether other AChR subunit mRNAs are co-transported","Independent replication in primary myotubes or in vivo"]},{"year":2013,"claim":"The interplay among splicing regulators at CHRNA1 intron 3 was unresolved; hnRNP L was found to bind CHRNA1 pre-mRNA and recruit PTB via its proline-rich domain, blocking U2AF65/U1 snRNP association with exon P3A, while its paralog hnRNP LL lacks this domain and antagonistically promotes inclusion — revealing an antagonistic switch that fine-tunes P3A splicing.","evidence":"Reciprocal co-immunoprecipitation of hnRNP L–PTB, siRNA knockdown, minigene splicing assays, RNA pulldown","pmids":["24121633"],"confidence":"High","gaps":["Relative expression levels of hnRNP L vs. hnRNP LL across muscle developmental stages","Whether hnRNP L/LL ratio is altered in myasthenic patients without known mutations"]},{"year":2021,"claim":"CHRNA1 function in non-muscle tissues was poorly defined; CHRNA1 upregulation in sweat glands was shown to drive excessive sweat secretion via downstream AQP5 and CACNA1C, establishing a non-canonical role for this receptor outside the neuromuscular junction.","evidence":"siRNA knockdown in pilocarpine-induced hyperhidrosis mouse model, TEM, ELISA, immunohistochemistry","pmids":["33476802"],"confidence":"Medium","gaps":["Whether CHRNA1 forms a canonical pentameric channel in sweat glands","Identity of the acetylcholine source activating glandular CHRNA1"]},{"year":2022,"claim":"Whether elevated CHRNA1 is a cause or consequence of age-related denervation was unknown; AAV9-mediated CHRNA1 overexpression in mouse hindlimb directly reduced NMJ innervation, muscle mass, and contractile function, establishing CHRNA1 gain-of-function as sufficient to drive sarcopenia-like pathology.","evidence":"AAV9-CHRNA1 injection in mouse hindlimb, immunofluorescence for innervation, electrophysiology, muscle morphometry","pmids":["35809807"],"confidence":"Medium","gaps":["Mechanism by which excess α1-subunit causes denervation","Whether CHRNA1 reduction in aged muscle is protective"]},{"year":2022,"claim":"Pharmacological targeting of CHRNA1 channel activity in hyperhidrosis was untested; cisatracurium was demonstrated to block CHRNA1 ion channel function and alleviate hyperhidrosis, with genetic epistasis (overexpression abolishes and knockdown precludes drug effect) proving on-target specificity.","evidence":"Heterologous CHRNA1 expression in HEK293 cells, cisatracurium treatment in hyperhidrosis mouse model, overexpression/siRNA epistasis","pmids":["35393764"],"confidence":"Medium","gaps":["Whether cisatracurium acts on homomeric α1 channels or requires co-expressed subunits","Clinical translatability to human hyperhidrosis"]},{"year":2022,"claim":"Whether coding variants outside intron 3 can cause P3A-dependent CMS was unclear; c.257G>A (p.Arg86His) was shown across nine kindreds to trigger exon P3A inclusion and produce a non-functional α1 subunit, causing AChR-deficiency CMS with distinctive facial and distal weakness.","evidence":"Whole-exome sequencing of 13 patients from nine kindreds, clinical phenotyping, molecular characterization of P3A inclusion","pmids":["36634413"],"confidence":"Medium","gaps":["Structural basis by which the Arg86His substitution promotes P3A inclusion","Whether this variant also affects receptor assembly independently of splicing"]},{"year":2023,"claim":"Upstream regulators of CHRNA1 in the sweat gland pathway were undefined; PAI1 (SERPINE1) was placed upstream of CHRNA1 as a negative regulator, with Serpine1 KO increasing and transgenic overexpression decreasing Chrna1 and hyperhidrosis markers, confirmed by CHRNA1-AAV rescue and cisatracurium epistasis.","evidence":"Serpine1 KO and Tg mice, pilocarpine hyperhidrosis model, Chrna1-AAV rescue, cisatracurium reversal, ELISA, RT-PCR, Western blot","pmids":["37542348"],"confidence":"Medium","gaps":["Mechanism by which PAI1 suppresses CHRNA1 transcription or stability","Whether PAI1–CHRNA1 axis operates in tissues beyond sweat glands"]},{"year":2025,"claim":"Post-transcriptional regulation of CHRNA1 levels in differentiating muscle was uncharacterized; circAtxn10 was identified as a miR-143-3p sponge that de-represses Chrna1 via three 3ʹ-UTR binding sites, and Chrna1 overexpression dramatically enhanced myotube formation, establishing a circRNA–miRNA–mRNA regulatory axis for myogenesis.","evidence":"RNA pulldown and luciferase reporters for circAtxn10–miR-143-3p and miR-143-3p–Chrna1 interactions, miRNA mimics, siRNA/overexpression, myogenic differentiation assays","pmids":["40701844"],"confidence":"Medium","gaps":["In vivo relevance of the circAtxn10–miR-143-3p–Chrna1 axis in muscle regeneration","Whether this axis is disrupted in myopathies"]},{"year":null,"claim":"The structural basis of exon P3A recognition by the hnRNP H/PTB/hnRNP L complex, the mechanism by which CHRNA1 overexpression causes denervation, and the signal linking PAI1 to CHRNA1 transcriptional repression remain unresolved.","evidence":"","pmids":[],"confidence":"Low","gaps":["No structural model of the ISS–hnRNP H–PTB ternary complex","Mechanism by which excess α1-subunit disrupts NMJ maintenance","Signal transduction pathway connecting PAI1 to CHRNA1 expression"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0005215","term_label":"transporter activity","supporting_discovery_ids":[7,5]}],"localization":[{"term_id":"GO:0005886","term_label":"plasma membrane","supporting_discovery_ids":[4,5,7]}],"pathway":[{"term_id":"R-HSA-112316","term_label":"Neuronal System","supporting_discovery_ids":[1,5,9]},{"term_id":"R-HSA-8953854","term_label":"Metabolism of RNA","supporting_discovery_ids":[1,2,3,10]},{"term_id":"R-HSA-168256","term_label":"Immune System","supporting_discovery_ids":[0]}],"complexes":["muscle nicotinic acetylcholine receptor (AChR)"],"partners":["HNRNPH1","PTBP1","HNRNPL","HNRNPLL","STAU1","SERPINE1"],"other_free_text":[]},"mechanistic_narrative":"CHRNA1 encodes the α1 subunit of the muscle nicotinic acetylcholine receptor (AChR), an essential ligand-gated ion channel component required for neuromuscular junction formation, AChR clustering, and myogenic differentiation. Alternative splicing of CHRNA1 pre-mRNA is tightly controlled by a network of RNA-binding proteins — hnRNP H and PTB bind an intronic silencer and polypyrimidine tract in intron 3 to suppress inclusion of the non-functional exon P3A, while hnRNP L promotes PTB binding and hnRNP LL antagonizes this suppression; disruption of this regulatory circuit by intronic or coding mutations causes AChR-deficiency congenital myasthenic syndrome [PMID:18806275, PMID:24121633, PMID:36634413]. CHRNA1 transcription in thymic epithelial cells is driven by IRF8 and AIRE to establish central self-tolerance, and its post-transcriptional levels in muscle are modulated by a circAtxn10–miR-143-3p sponge axis and by Stau1-dependent mRNA localization to postsynaptic sites [PMID:17687331, PMID:40701844, PMID:22884571]. Gain-of-function studies show that CHRNA1 overexpression in skeletal muscle drives sarcopenia-like denervation and atrophy, while in sweat glands it promotes excessive secretion through a PAI1-regulated pathway amenable to pharmacological blockade by cisatracurium [PMID:35809807, PMID:37542348, PMID:35393764]."},"prefetch_data":{"uniprot":{"accession":"P02708","full_name":"Acetylcholine receptor subunit alpha","aliases":[],"length_aa":457,"mass_kda":51.8,"function":"Upon acetylcholine binding, the AChR responds by an extensive change in conformation that affects all subunits and leads to opening of an ion-conducting channel across the plasma membrane Non functional acetylcholine receptor alpha subunit which is not integrated into functional acetylcholine-gated cation-selective channels","subcellular_location":"Postsynaptic cell membrane; Cell membrane","url":"https://www.uniprot.org/uniprotkb/P02708/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/CHRNA1","classification":"Not Classified","n_dependent_lines":0,"n_total_lines":1208,"dependency_fraction":0.0},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/CHRNA1","total_profiled":1310},"omim":[{"mim_id":"618388","title":"FETAL AKINESIA DEFORMATION SEQUENCE 2; FADS2","url":"https://www.omim.org/entry/618388"},{"mim_id":"617372","title":"SHC TRANSFORMING PROTEIN 4; SHC4","url":"https://www.omim.org/entry/617372"},{"mim_id":"616322","title":"MYASTHENIC SYNDROME, CONGENITAL, 3B, FAST-CHANNEL; CMS3B","url":"https://www.omim.org/entry/616322"},{"mim_id":"608930","title":"MYASTHENIC SYNDROME, CONGENITAL, 1B, FAST-CHANNEL; CMS1B","url":"https://www.omim.org/entry/608930"},{"mim_id":"607358","title":"AUTOIMMUNE REGULATOR; AIRE","url":"https://www.omim.org/entry/607358"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Supported","locations":[{"location":"Plasma membrane","reliability":"Supported"}],"tissue_specificity":"Tissue enriched","tissue_distribution":"Detected in some","driving_tissues":[{"tissue":"skeletal muscle","ntpm":160.2}],"url":"https://www.proteinatlas.org/search/CHRNA1"},"hgnc":{"alias_symbol":[],"prev_symbol":["CHRNA"]},"alphafold":{"accession":"P02708","domains":[{"cath_id":"2.70.170.10","chopping":"25-82_104-255","consensus_level":"high","plddt":89.6282,"start":25,"end":255},{"cath_id":"1.20.58.390","chopping":"259-372_417-482","consensus_level":"high","plddt":87.1926,"start":259,"end":482}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/P02708","model_url":"https://alphafold.ebi.ac.uk/files/AF-P02708-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-P02708-F1-predicted_aligned_error_v6.png","plddt_mean":84.0},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=CHRNA1","jax_strain_url":"https://www.jax.org/strain/search?query=CHRNA1"},"sequence":{"accession":"P02708","fasta_url":"https://rest.uniprot.org/uniprotkb/P02708.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/P02708/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/P02708"}},"corpus_meta":[{"pmid":"17687331","id":"PMC_17687331","title":"An IRF8-binding promoter variant and AIRE control CHRNA1 promiscuous expression in thymus.","date":"2007","source":"Nature","url":"https://pubmed.ncbi.nlm.nih.gov/17687331","citation_count":147,"is_preprint":false},{"pmid":"19010884","id":"PMC_19010884","title":"Smokers with the CHRNA lung cancer-associated variants are exposed to higher levels of nicotine equivalents and a carcinogenic tobacco-specific nitrosamine.","date":"2008","source":"Cancer research","url":"https://pubmed.ncbi.nlm.nih.gov/19010884","citation_count":124,"is_preprint":false},{"pmid":"18179903","id":"PMC_18179903","title":"Mutation analysis of CHRNA1, CHRNB1, CHRND, and RAPSN genes in multiple pterygium syndrome/fetal akinesia patients.","date":"2008","source":"American journal of human genetics","url":"https://pubmed.ncbi.nlm.nih.gov/18179903","citation_count":81,"is_preprint":false},{"pmid":"7910962","id":"PMC_7910962","title":"Involvement of human muscle acetylcholine receptor alpha-subunit gene (CHRNA) in susceptibility to myasthenia gravis.","date":"1994","source":"Proceedings of the National Academy of Sciences of the United States of America","url":"https://pubmed.ncbi.nlm.nih.gov/7910962","citation_count":64,"is_preprint":false},{"pmid":"18806275","id":"PMC_18806275","title":"hnRNP H enhances skipping of a nonfunctional exon P3A in CHRNA1 and a mutation disrupting its binding causes congenital myasthenic syndrome.","date":"2008","source":"Human molecular genetics","url":"https://pubmed.ncbi.nlm.nih.gov/18806275","citation_count":52,"is_preprint":false},{"pmid":"24121633","id":"PMC_24121633","title":"HnRNP L and hnRNP LL antagonistically modulate PTB-mediated splicing suppression of CHRNA1 pre-mRNA.","date":"2013","source":"Scientific reports","url":"https://pubmed.ncbi.nlm.nih.gov/24121633","citation_count":39,"is_preprint":false},{"pmid":"19147685","id":"PMC_19147685","title":"Tannic acid facilitates expression of the polypyrimidine tract binding protein and alleviates deleterious inclusion of CHRNA1 exon P3A due to an hnRNP H-disrupting mutation in congenital myasthenic syndrome.","date":"2009","source":"Human molecular genetics","url":"https://pubmed.ncbi.nlm.nih.gov/19147685","citation_count":29,"is_preprint":false},{"pmid":"8738961","id":"PMC_8738961","title":"Human muscle acetylcholine receptor alpha-subunit gene (CHRNA1) association with autoimmune myasthenia gravis in black, mixed-ancestry and Caucasian subjects.","date":"1996","source":"Journal of autoimmunity","url":"https://pubmed.ncbi.nlm.nih.gov/8738961","citation_count":26,"is_preprint":false},{"pmid":"9237805","id":"PMC_9237805","title":"Association of the AChRalpha-subunit gene (CHRNA), DQA1*0101, and the DR3 haplotype in myasthenia gravis. Evidence for a three-gene disease model in a subgroup of patients.","date":"1997","source":"Journal of autoimmunity","url":"https://pubmed.ncbi.nlm.nih.gov/9237805","citation_count":23,"is_preprint":false},{"pmid":"28494468","id":"PMC_28494468","title":"Genes Involved in Neurodevelopment, Neuroplasticity, and Bipolar Disorder: CACNA1C, CHRNA1, and MAPK1.","date":"2017","source":"Neuropsychobiology","url":"https://pubmed.ncbi.nlm.nih.gov/28494468","citation_count":19,"is_preprint":false},{"pmid":"25279974","id":"PMC_25279974","title":"Role of SLCO1B1, ABCB1, and CHRNA1 gene polymorphisms on the efficacy of rocuronium in Chinese patients.","date":"2014","source":"Journal of clinical pharmacology","url":"https://pubmed.ncbi.nlm.nih.gov/25279974","citation_count":16,"is_preprint":false},{"pmid":"20157724","id":"PMC_20157724","title":"Identification of previously unreported mutations in CHRNA1, CHRNE and RAPSN genes in three unrelated Italian patients with congenital myasthenic syndromes.","date":"2010","source":"Journal of neurology","url":"https://pubmed.ncbi.nlm.nih.gov/20157724","citation_count":14,"is_preprint":false},{"pmid":"23775407","id":"PMC_23775407","title":"High expression of CHRNA1 is associated with reduced survival in early stage lung adenocarcinoma after complete resection.","date":"2013","source":"Annals of surgical oncology","url":"https://pubmed.ncbi.nlm.nih.gov/23775407","citation_count":12,"is_preprint":false},{"pmid":"35809807","id":"PMC_35809807","title":"CHRNA1 induces sarcopenia through neuromuscular synaptic elimination.","date":"2022","source":"Experimental gerontology","url":"https://pubmed.ncbi.nlm.nih.gov/35809807","citation_count":11,"is_preprint":false},{"pmid":"33476802","id":"PMC_33476802","title":"CHRNA1 promotes the pathogenesis of primary focal hyperhidrosis.","date":"2021","source":"Molecular and cellular neurosciences","url":"https://pubmed.ncbi.nlm.nih.gov/33476802","citation_count":11,"is_preprint":false},{"pmid":"22884571","id":"PMC_22884571","title":"Agrin induces association of Chrna1 mRNA and nicotinic acetylcholine receptor in C2C12 myotubes.","date":"2012","source":"FEBS letters","url":"https://pubmed.ncbi.nlm.nih.gov/22884571","citation_count":10,"is_preprint":false},{"pmid":"23232035","id":"PMC_23232035","title":"Association study of nicotinic acetylcholine receptor genes identifies a novel lung cancer susceptibility locus near CHRNA1 in African-Americans.","date":"2012","source":"Oncotarget","url":"https://pubmed.ncbi.nlm.nih.gov/23232035","citation_count":9,"is_preprint":false},{"pmid":"36276121","id":"PMC_36276121","title":"Epidemiological evidence for associations between variants in CHRNA genes and risk of lung cancer and chronic obstructive pulmonary disease.","date":"2022","source":"Frontiers in oncology","url":"https://pubmed.ncbi.nlm.nih.gov/36276121","citation_count":8,"is_preprint":false},{"pmid":"36634413","id":"PMC_36634413","title":"A novel phenotype of AChR-deficiency syndrome with predominant facial and distal weakness resulting from the inclusion of an evolutionary alternatively-spliced exon in CHRNA1.","date":"2022","source":"Neuromuscular disorders : NMD","url":"https://pubmed.ncbi.nlm.nih.gov/36634413","citation_count":6,"is_preprint":false},{"pmid":"35393764","id":"PMC_35393764","title":"Antagonist of Chrna1 prevents the pathogenesis of primary focal hyperhidrosis.","date":"2022","source":"Annals of clinical and translational neurology","url":"https://pubmed.ncbi.nlm.nih.gov/35393764","citation_count":5,"is_preprint":false},{"pmid":"23448903","id":"PMC_23448903","title":"Clinical phenotype and the lack of mutations in the CHRNG, CHRND, and CHRNA1 genes in two Indian families with Escobar syndrome.","date":"2013","source":"Clinical dysmorphology","url":"https://pubmed.ncbi.nlm.nih.gov/23448903","citation_count":5,"is_preprint":false},{"pmid":"17868079","id":"PMC_17868079","title":"Analysis and mapping of CACNB4, CHRNA1, KCNJ3, SCN2A and SPG4, physiological candidate genes for porcine congenital progressive ataxia and spastic paresis.","date":"2007","source":"Journal of animal breeding and genetics = Zeitschrift fur Tierzuchtung und Zuchtungsbiologie","url":"https://pubmed.ncbi.nlm.nih.gov/17868079","citation_count":5,"is_preprint":false},{"pmid":"37542348","id":"PMC_37542348","title":"PAI1 inhibits the pathogenesis of primary focal hyperhidrosis by targeting CHRNA1.","date":"2023","source":"Orphanet journal of rare diseases","url":"https://pubmed.ncbi.nlm.nih.gov/37542348","citation_count":4,"is_preprint":false},{"pmid":"36092864","id":"PMC_36092864","title":"Case Report: Novel compound heterozygous variants in CHRNA1 gene leading to lethal multiple pterygium syndrome: A case report.","date":"2022","source":"Frontiers in genetics","url":"https://pubmed.ncbi.nlm.nih.gov/36092864","citation_count":3,"is_preprint":false},{"pmid":"40279038","id":"PMC_40279038","title":"Causal Variants in CHRNA1 and CHRNB1 Genes for Anti-acetylcholine Receptor Antibody Positive Myasthenia Gravis: Evidence from Bayesian Fine-Mapping and Genetic Association Study.","date":"2025","source":"Molecular neurobiology","url":"https://pubmed.ncbi.nlm.nih.gov/40279038","citation_count":2,"is_preprint":false},{"pmid":"40503176","id":"PMC_40503176","title":"PAI1 regulating CHRNA1 contributes to primary focal hyperhidrosis: Clinical and experimental studies.","date":"2025","source":"Molecular therapy. Nucleic acids","url":"https://pubmed.ncbi.nlm.nih.gov/40503176","citation_count":1,"is_preprint":false},{"pmid":"40701844","id":"PMC_40701844","title":"Circular RNA circAtxn10 regulates skeletal muscle cell differentiation by targeting miR-143-3p and Chrna1.","date":"2025","source":"The Korean journal of physiology & pharmacology : official journal of the Korean Physiological Society and the Korean Society of Pharmacology","url":"https://pubmed.ncbi.nlm.nih.gov/40701844","citation_count":1,"is_preprint":false},{"pmid":null,"id":"bio_10.1101_2025.11.20.25340674","title":"Building and sustaining trust across communities: Lessons from a large-scale, community-based cancer needs assessment in New York City","date":"2025-11-21","source":"bioRxiv","url":"https://doi.org/10.1101/2025.11.20.25340674","citation_count":0,"is_preprint":true},{"pmid":null,"id":"bio_10.1101_2025.10.31.685856","title":"Deficient Cardiolipin Remodeling Alters Muscle Fiber Composition and Neuromuscular Connectivity in Barth Syndrome","date":"2025-11-03","source":"bioRxiv","url":"https://doi.org/10.1101/2025.10.31.685856","citation_count":0,"is_preprint":true},{"pmid":null,"id":"bio_10.1101_2025.10.16.681134","title":"Repeated disuse atrophy imprints a molecular memory in skeletal muscle: transcriptional resilience in young adults and susceptibility in aged muscle","date":"2025-10-16","source":"bioRxiv","url":"https://doi.org/10.1101/2025.10.16.681134","citation_count":0,"is_preprint":true},{"pmid":null,"id":"bio_10.1101_2025.06.30.662345","title":"Comparative toxicity of menthol- and tobacco-flavored electronic cigarette constituents causing inflammation, epithelial barrier dysfunction, and nicotinic acetylcholine receptor modulation in the absence of nicotine","date":"2025-07-04","source":"bioRxiv","url":"https://doi.org/10.1101/2025.06.30.662345","citation_count":0,"is_preprint":true},{"pmid":null,"id":"bio_10.1101_2024.10.04.616757","title":"Cholinergic regulation of sleep in the upside-down jellyfish<i>Cassiopea</i>","date":"2024-10-05","source":"bioRxiv","url":"https://doi.org/10.1101/2024.10.04.616757","citation_count":0,"is_preprint":true}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":17175,"output_tokens":3122,"usd":0.049177},"stage2":{"model":"claude-opus-4-6","input_tokens":6499,"output_tokens":3288,"usd":0.172042},"total_usd":0.221219,"stage1_batch_id":"msgbatch_011kfMfE81o6CTcyhVUqumuW","stage2_batch_id":"msgbatch_01DTputS6WNkH745x1nVSoBo","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2007,\n      \"finding\": \"IRF8 binds the CHRNA1 promoter and drives its transcription in thymic epithelial cells; a promoter variant prevents IRF8 binding and abrogates CHRNA1 promoter activity. AIRE also transactivates CHRNA1 in medullary thymic epithelial cells, and together IRF8 and AIRE regulate promiscuous CHRNA1 expression to set the threshold for self-tolerance.\",\n      \"method\": \"Promoter re-sequencing, in vitro transcription/binding assays (IRF8–promoter interaction), transactivation assay in thymic epithelial cells, ex vivo mRNA quantification from human medullary thymic epithelial cells\",\n      \"journal\": \"Nature\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — multiple orthogonal methods (binding assay, transactivation, ex vivo), replicated across two independent human populations\",\n      \"pmids\": [\"17687331\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2008,\n      \"finding\": \"hnRNP H binds an intronic splicing silencer (ISS) near the 3' end of CHRNA1 intron 3 and promotes skipping of the non-functional exon P3A; a congenital myasthenic syndrome mutation (IVS3-8G>A) disrupts the ISS, reduces hnRNP H affinity ~100-fold, and causes exclusive inclusion of exon P3A, producing a non-functional acetylcholine receptor α-subunit.\",\n      \"method\": \"Patient mutation identification, in vitro binding/affinity assays (ISS–hnRNP H), siRNA knockdown of hnRNP H, hnRNP H tethering assay, minigene splicing reporter\",\n      \"journal\": \"Human molecular genetics\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1–2 — reconstitution of splicing mechanism, mutagenesis, siRNA, and tethering assay in a single study\",\n      \"pmids\": [\"18806275\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2009,\n      \"finding\": \"Polypyrimidine tract binding protein (PTB) binds near the 3' end of CHRNA1 intron 3 and induces skipping of exon P3A; tannic acid increases PTB expression and ameliorates aberrant exon P3A inclusion caused by the IVS3-8G>A mutation without altering hnRNP H levels.\",\n      \"method\": \"PTB deletion/binding assays, PTB promoter deletion analysis, compound screen (960 bioactive compounds), tannic acid dose–response for PTB expression\",\n      \"journal\": \"Human molecular genetics\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — functional binding and promoter assays in single lab with chemical validation\",\n      \"pmids\": [\"19147685\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"hnRNP L binds hnRNP L-binding sites in CHRNA1 pre-mRNA and interacts with PTB through its proline-rich region, promoting PTB binding to the polypyrimidine tract upstream of exon P3A; this inhibits U2AF65 and U1 snRNP association, blocking exon P3A definition and thus promoting exon skipping. hnRNP LL, which lacks the proline-rich region, cannot bind PTB and instead promotes exon P3A inclusion — the two proteins antagonistically modulate PTB-mediated splicing suppression.\",\n      \"method\": \"Co-immunoprecipitation (hnRNP L–PTB interaction), siRNA knockdown, minigene splicing assays, patient mutation analysis, RNA pulldown\",\n      \"journal\": \"Scientific reports\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — reciprocal Co-IP, siRNA, and minigene reporter with mechanistic epistasis in a single study\",\n      \"pmids\": [\"24121633\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"Agrin stimulation induces co-localization of Chrna1 mRNA with assembled nicotinic acetylcholine receptor (AChR) at postsynaptic clusters in C2C12 myotubes; Stau1 protein interacts with Chrna1 mRNA, and Stau1 knockdown causes defective AChR clustering, implicating mRNA localization in neuromuscular junction formation.\",\n      \"method\": \"RT-PCR of AChR affinity-column and ultracentrifugation fractions, RNA immunoprecipitation (Stau1–Chrna1 mRNA), RNAi knockdown of Stau1, AChR clustering assay\",\n      \"journal\": \"FEBS letters\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2–3 — pulldown and functional knockdown in single lab with defined cellular phenotype\",\n      \"pmids\": [\"22884571\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"AAV9-mediated overexpression of CHRNA1 in hindlimb muscle decreases neuromuscular junction innervation percentage and reduces skeletal muscle mass (gastrocnemius mass index and fiber cross-sectional area), compound muscle action potential, and contractility, demonstrating that elevated CHRNA1 drives sarcopenia-like muscle denervation and atrophy.\",\n      \"method\": \"AAV9-CHRNA1 local injection in mouse hindlimb, immunofluorescence for innervation, electrophysiology (compound muscle action potential), muscle mass/fiber morphometry\",\n      \"journal\": \"Experimental gerontology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — in vivo gain-of-function with multiple orthogonal readouts in single study\",\n      \"pmids\": [\"35809807\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"CHRNA1 upregulation in sweat glands promotes excessive sweat secretion; siRNA-mediated CHRNA1 silencing decreases sweat secretion, reduces sweat secretory granules, lowers serum acetylcholine, and downregulates AQP5 and CACNA1C in sweat glands, as well as BDNF and NRG-1 in sympathetic ganglia axons.\",\n      \"method\": \"siRNA knockdown in pilocarpine-induced hyperhidrosis mouse model, transmission electron microscopy, ELISA, immunohistochemistry, Western blot, qRT-PCR\",\n      \"journal\": \"Molecular and cellular neurosciences\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — loss-of-function with multiple molecular readouts in in vivo model, single lab\",\n      \"pmids\": [\"33476802\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"Cisatracurium, an antagonist of CHRNA1, blocks the CHRNA1 ion channel (without altering CHRNA1 gene or protein expression) and alleviates hyperhidrosis in mice; overexpression of CHRNA1 abolishes cisatracurium's effect while CHRNA1 knockdown prevents additional benefit, establishing that cisatracurium acts specifically through CHRNA1 channel blockade.\",\n      \"method\": \"HEK293 cell expression of Chrna1, cisatracurium treatment in vivo (hyperhidrosis mouse model), CHRNA1 overexpression/siRNA epistasis experiments, sweat secretion quantification, Western blot\",\n      \"journal\": \"Annals of clinical and translational neurology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — pharmacological channel blockade validated by genetic epistasis (OE and KD) in single lab\",\n      \"pmids\": [\"35393764\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"PAI1 (SERPINE1) negatively regulates CHRNA1 expression in sweat glands; Serpine1 knockout increases Chrna1 expression and hyperhidrosis markers (ACH, CACNA1C, AQP5), while Serpine1 transgenic overexpression reduces them. CHRNA1-expressing AAV rescues hyperhidrosis in Serpine1-Tg mice, and CHRNA1 antagonist cisatracurium reverses the Pai1-KO hyperhidrosis phenotype, placing PAI1 upstream of CHRNA1 in this pathway.\",\n      \"method\": \"Serpine1 KO and Tg mice, pilocarpine hyperhidrosis model, Chrna1-expressing AAV rescue, cisatracurium antagonism, ELISA, RT-PCR, Western blot\",\n      \"journal\": \"Orphanet journal of rare diseases\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — genetic epistasis across KO, Tg, and AAV rescue with pharmacological corroboration in single lab\",\n      \"pmids\": [\"37542348\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"The CHRNA1 variant c.257G>A (p.Arg86His) causes inclusion of the alternatively-spliced evolutionary exon P3A, producing a non-functional AChR α-subunit that leads to AChR-deficiency congenital myasthenic syndrome with a distinctive phenotype of facial and distal weakness.\",\n      \"method\": \"Whole-exome sequencing of 13 patients from nine kindreds, clinical phenotyping, molecular characterization of P3A inclusion\",\n      \"journal\": \"Neuromuscular disorders : NMD\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 — genotype–phenotype correlation across multiple families; functional mechanism of P3A inclusion inferred from prior mechanistic studies\",\n      \"pmids\": [\"36634413\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"circAtxn10 acts as a sponge for miR-143-3p through direct binding; miR-143-3p directly targets three binding sites in the Chrna1 3'-UTR to suppress its expression. Chrna1 knockdown impairs myogenesis, while Chrna1 overexpression dramatically enhances myogenic marker expression and myotube formation, establishing a circAtxn10–miR-143-3p–Chrna1 regulatory axis in skeletal muscle differentiation.\",\n      \"method\": \"RNA pulldown/luciferase reporter for circAtxn10–miR-143-3p interaction, 3'-UTR luciferase reporter for miR-143-3p–Chrna1 targeting, miR-143-3p mimic, siRNA knockdown and overexpression of Chrna1, myogenic differentiation assays\",\n      \"journal\": \"The Korean journal of physiology & pharmacology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — direct RNA interaction validation plus loss- and gain-of-function with defined myogenic phenotype in single lab\",\n      \"pmids\": [\"40701844\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"CHRNA1 encodes the muscle nicotinic acetylcholine receptor α1-subunit, an ion channel subunit whose expression and splicing are mechanistically regulated by IRF8/AIRE at the promoter level, and by hnRNP H, PTB, hnRNP L, hnRNP LL, and a circAtxn10–miR-143-3p axis at the pre-mRNA splicing/localization level; the alternatively-spliced exon P3A produces a non-functional subunit whose inclusion is suppressed by hnRNP H and PTB in normal muscle, and CHRNA1 protein at the neuromuscular junction is required for proper AChR clustering, muscle innervation, and myogenic differentiation, while its upregulation drives sarcopenia-like denervation and pathological sweat secretion through a PAI1-regulated pathway.\"\n}\n```","stage2_raw":"```json\n{\n  \"mechanistic_narrative\": \"CHRNA1 encodes the α1 subunit of the muscle nicotinic acetylcholine receptor (AChR), an essential ligand-gated ion channel component required for neuromuscular junction formation, AChR clustering, and myogenic differentiation. Alternative splicing of CHRNA1 pre-mRNA is tightly controlled by a network of RNA-binding proteins — hnRNP H and PTB bind an intronic silencer and polypyrimidine tract in intron 3 to suppress inclusion of the non-functional exon P3A, while hnRNP L promotes PTB binding and hnRNP LL antagonizes this suppression; disruption of this regulatory circuit by intronic or coding mutations causes AChR-deficiency congenital myasthenic syndrome [PMID:18806275, PMID:24121633, PMID:36634413]. CHRNA1 transcription in thymic epithelial cells is driven by IRF8 and AIRE to establish central self-tolerance, and its post-transcriptional levels in muscle are modulated by a circAtxn10–miR-143-3p sponge axis and by Stau1-dependent mRNA localization to postsynaptic sites [PMID:17687331, PMID:40701844, PMID:22884571]. Gain-of-function studies show that CHRNA1 overexpression in skeletal muscle drives sarcopenia-like denervation and atrophy, while in sweat glands it promotes excessive secretion through a PAI1-regulated pathway amenable to pharmacological blockade by cisatracurium [PMID:35809807, PMID:37542348, PMID:35393764].\",\n  \"teleology\": [\n    {\n      \"year\": 2007,\n      \"claim\": \"How CHRNA1 is transcribed outside muscle was unknown; discovery that IRF8 and AIRE directly transactivate the CHRNA1 promoter in thymic epithelial cells established the mechanism for promiscuous thymic expression underlying central tolerance to AChR.\",\n      \"evidence\": \"Promoter sequencing, IRF8–DNA binding assays, transactivation assays, and ex vivo mRNA quantification in human medullary thymic epithelial cells\",\n      \"pmids\": [\"17687331\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Whether IRF8/AIRE regulation extends to other AChR subunit genes\", \"Mechanism linking reduced thymic CHRNA1 expression to autoimmune myasthenia gravis susceptibility\"]\n    },\n    {\n      \"year\": 2008,\n      \"claim\": \"The mechanism enforcing skipping of the non-functional exon P3A was undefined; identification of hnRNP H binding to an intronic splicing silencer in intron 3, and demonstration that a patient mutation (IVS3-8G>A) abolishes this binding to cause constitutive P3A inclusion, established the first cis-regulatory element and trans-acting factor controlling CHRNA1 alternative splicing.\",\n      \"evidence\": \"Patient mutation identification, in vitro binding/affinity measurements, siRNA knockdown, hnRNP H tethering assay, minigene splicing reporter\",\n      \"pmids\": [\"18806275\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Structural basis of hnRNP H–ISS recognition\", \"Whether additional splicing factors cooperate with hnRNP H at this element\"]\n    },\n    {\n      \"year\": 2009,\n      \"claim\": \"Whether other splicing regulators independently control P3A skipping was unclear; PTB was shown to bind near intron 3 and suppress P3A inclusion, and tannic acid was identified as a PTB inducer that ameliorates aberrant splicing caused by the IVS3-8G>A mutation.\",\n      \"evidence\": \"PTB binding/deletion assays, promoter analysis, bioactive compound screen, tannic acid dose–response\",\n      \"pmids\": [\"19147685\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"In vivo efficacy of tannic acid for CMS\", \"Whether PTB and hnRNP H act independently or cooperatively at intron 3\"]\n    },\n    {\n      \"year\": 2012,\n      \"claim\": \"How CHRNA1 mRNA is positioned at the neuromuscular synapse was unknown; Stau1 was shown to bind Chrna1 mRNA and mediate its co-localization with AChR clusters upon agrin stimulation, linking mRNA transport to postsynaptic differentiation.\",\n      \"evidence\": \"RNA immunoprecipitation (Stau1–Chrna1 mRNA), RNAi knockdown, AChR clustering assay in C2C12 myotubes\",\n      \"pmids\": [\"22884571\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Cis-element in Chrna1 mRNA recognized by Stau1\", \"Whether other AChR subunit mRNAs are co-transported\", \"Independent replication in primary myotubes or in vivo\"]\n    },\n    {\n      \"year\": 2013,\n      \"claim\": \"The interplay among splicing regulators at CHRNA1 intron 3 was unresolved; hnRNP L was found to bind CHRNA1 pre-mRNA and recruit PTB via its proline-rich domain, blocking U2AF65/U1 snRNP association with exon P3A, while its paralog hnRNP LL lacks this domain and antagonistically promotes inclusion — revealing an antagonistic switch that fine-tunes P3A splicing.\",\n      \"evidence\": \"Reciprocal co-immunoprecipitation of hnRNP L–PTB, siRNA knockdown, minigene splicing assays, RNA pulldown\",\n      \"pmids\": [\"24121633\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Relative expression levels of hnRNP L vs. hnRNP LL across muscle developmental stages\", \"Whether hnRNP L/LL ratio is altered in myasthenic patients without known mutations\"]\n    },\n    {\n      \"year\": 2021,\n      \"claim\": \"CHRNA1 function in non-muscle tissues was poorly defined; CHRNA1 upregulation in sweat glands was shown to drive excessive sweat secretion via downstream AQP5 and CACNA1C, establishing a non-canonical role for this receptor outside the neuromuscular junction.\",\n      \"evidence\": \"siRNA knockdown in pilocarpine-induced hyperhidrosis mouse model, TEM, ELISA, immunohistochemistry\",\n      \"pmids\": [\"33476802\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Whether CHRNA1 forms a canonical pentameric channel in sweat glands\", \"Identity of the acetylcholine source activating glandular CHRNA1\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Whether elevated CHRNA1 is a cause or consequence of age-related denervation was unknown; AAV9-mediated CHRNA1 overexpression in mouse hindlimb directly reduced NMJ innervation, muscle mass, and contractile function, establishing CHRNA1 gain-of-function as sufficient to drive sarcopenia-like pathology.\",\n      \"evidence\": \"AAV9-CHRNA1 injection in mouse hindlimb, immunofluorescence for innervation, electrophysiology, muscle morphometry\",\n      \"pmids\": [\"35809807\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Mechanism by which excess α1-subunit causes denervation\", \"Whether CHRNA1 reduction in aged muscle is protective\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Pharmacological targeting of CHRNA1 channel activity in hyperhidrosis was untested; cisatracurium was demonstrated to block CHRNA1 ion channel function and alleviate hyperhidrosis, with genetic epistasis (overexpression abolishes and knockdown precludes drug effect) proving on-target specificity.\",\n      \"evidence\": \"Heterologous CHRNA1 expression in HEK293 cells, cisatracurium treatment in hyperhidrosis mouse model, overexpression/siRNA epistasis\",\n      \"pmids\": [\"35393764\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Whether cisatracurium acts on homomeric α1 channels or requires co-expressed subunits\", \"Clinical translatability to human hyperhidrosis\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Whether coding variants outside intron 3 can cause P3A-dependent CMS was unclear; c.257G>A (p.Arg86His) was shown across nine kindreds to trigger exon P3A inclusion and produce a non-functional α1 subunit, causing AChR-deficiency CMS with distinctive facial and distal weakness.\",\n      \"evidence\": \"Whole-exome sequencing of 13 patients from nine kindreds, clinical phenotyping, molecular characterization of P3A inclusion\",\n      \"pmids\": [\"36634413\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Structural basis by which the Arg86His substitution promotes P3A inclusion\", \"Whether this variant also affects receptor assembly independently of splicing\"]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"Upstream regulators of CHRNA1 in the sweat gland pathway were undefined; PAI1 (SERPINE1) was placed upstream of CHRNA1 as a negative regulator, with Serpine1 KO increasing and transgenic overexpression decreasing Chrna1 and hyperhidrosis markers, confirmed by CHRNA1-AAV rescue and cisatracurium epistasis.\",\n      \"evidence\": \"Serpine1 KO and Tg mice, pilocarpine hyperhidrosis model, Chrna1-AAV rescue, cisatracurium reversal, ELISA, RT-PCR, Western blot\",\n      \"pmids\": [\"37542348\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Mechanism by which PAI1 suppresses CHRNA1 transcription or stability\", \"Whether PAI1–CHRNA1 axis operates in tissues beyond sweat glands\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Post-transcriptional regulation of CHRNA1 levels in differentiating muscle was uncharacterized; circAtxn10 was identified as a miR-143-3p sponge that de-represses Chrna1 via three 3ʹ-UTR binding sites, and Chrna1 overexpression dramatically enhanced myotube formation, establishing a circRNA–miRNA–mRNA regulatory axis for myogenesis.\",\n      \"evidence\": \"RNA pulldown and luciferase reporters for circAtxn10–miR-143-3p and miR-143-3p–Chrna1 interactions, miRNA mimics, siRNA/overexpression, myogenic differentiation assays\",\n      \"pmids\": [\"40701844\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"In vivo relevance of the circAtxn10–miR-143-3p–Chrna1 axis in muscle regeneration\", \"Whether this axis is disrupted in myopathies\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"The structural basis of exon P3A recognition by the hnRNP H/PTB/hnRNP L complex, the mechanism by which CHRNA1 overexpression causes denervation, and the signal linking PAI1 to CHRNA1 transcriptional repression remain unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"No structural model of the ISS–hnRNP H–PTB ternary complex\", \"Mechanism by which excess α1-subunit disrupts NMJ maintenance\", \"Signal transduction pathway connecting PAI1 to CHRNA1 expression\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\n        \"term_id\": \"GO:0005215\",\n        \"supporting_discovery_ids\": [7, 5]\n      }\n    ],\n    \"localization\": [\n      {\n        \"term_id\": \"GO:0005886\",\n        \"supporting_discovery_ids\": [4, 5, 7]\n      }\n    ],\n    \"pathway\": [\n      {\n        \"term_id\": \"R-HSA-112316\",\n        \"supporting_discovery_ids\": [1, 5, 9]\n      },\n      {\n        \"term_id\": \"R-HSA-8953854\",\n        \"supporting_discovery_ids\": [1, 2, 3, 10]\n      },\n      {\n        \"term_id\": \"R-HSA-168256\",\n        \"supporting_discovery_ids\": [0]\n      }\n    ],\n    \"complexes\": [\n      \"muscle nicotinic acetylcholine receptor (AChR)\"\n    ],\n    \"partners\": [\n      \"HNRNPH1\",\n      \"PTBP1\",\n      \"HNRNPL\",\n      \"HNRNPLL\",\n      \"STAU1\",\n      \"SERPINE1\"\n    ],\n    \"other_free_text\": []\n  }\n}\n```"}