{"gene":"CNIH3","run_date":"2026-04-28T17:28:52","timeline":{"discoveries":[{"year":2019,"finding":"Cryo-EM structures of AMPAR in complex with CNIH3 revealed that CNIH3 lacks an extracellular domain and instead contains four membrane-spanning helices, contrary to its predicted membrane topology. The protein-protein interaction interface between CNIH3 and the AMPAR that dictates channel modulation was identified, along with surrounding lipids.","method":"High-resolution cryo-electron microscopy structural determination","journal":"Science","confidence":"High","confidence_rationale":"Tier 1 — cryo-EM structure with functional validation, single rigorous paper resolving topology and interaction interface","pmids":["31806817"],"is_preprint":false},{"year":2013,"finding":"Using CNIH-2 and CNIH-3 conditional knockout mice, CNIH-2/-3 were shown to be required for surface expression of GluA1-containing AMPARs (GluA1A2 heteromers) at hippocampal synapses. Loss of CNIHs resulted in a profound reduction of AMPAR synaptic transmission, leaving only a residual pool of GluA2A3 heteromers. The selective effect of CNIHs on GluA1 is mediated via TARP γ-8, which prevents functional association of CNIHs with non-GluA1 subunits.","method":"Conditional knockout mice, electrophysiology, surface biotinylation, co-immunoprecipitation","journal":"Neuron","confidence":"High","confidence_rationale":"Tier 2 — conditional KO with specific cellular phenotype, multiple orthogonal methods, highly cited","pmids":["23522044"],"is_preprint":false},{"year":2012,"finding":"CNIH-3 (but not CNIH-1) slows the deactivation and desensitization of both GluA2-containing calcium-impermeable and GluA2-lacking calcium-permeable AMPARs expressed in heterologous cells. CNIH-2 and CNIH-3 also enhanced glutamate sensitivity, single-channel conductance, and calcium permeability of calcium-permeable AMPARs, while decreasing their block by intracellular polyamines. Overexpression of CNIH-3 in oligodendrocyte precursor cells markedly slowed AMPAR desensitization.","method":"Electrophysiology in tsA201 cells and native glial cells, overexpression, antibody surface labeling","journal":"The Journal of Neuroscience","confidence":"High","confidence_rationale":"Tier 1-2 — in vitro reconstitution with electrophysiological assays in heterologous and native cells, replicated across conditions","pmids":["22815494"],"is_preprint":false},{"year":2014,"finding":"CNIH-3 forms a stable complex with tetrameric AMPARs and contributes to the transmembrane density in single-particle electron microscopy structures. Peptide array-based screening and in vitro mutagenesis identified two clusters of conserved membrane-proximal residues in CNIHs that contribute to AMPAR binding. Residues in the extracellular loop of CNIH-2/3 absent in CNIH-1/4 are critical for both AMPAR interaction and gating modulation. The AMPAR ligand-binding domain (and possibly a linker connecting it to the fourth membrane-spanning segment) is the principal contact point with the CNIH-3 extracellular loop. A mutant CNIH-3 was identified that preserves AMPAR binding but has attenuated gating modulation.","method":"Single-particle electron microscopy, peptide array screening, in vitro mutagenesis, co-immunoprecipitation, electrophysiology","journal":"The Journal of Neuroscience","confidence":"High","confidence_rationale":"Tier 1-2 — multiple orthogonal methods including structure, mutagenesis, and functional assays in single study","pmids":["25186755"],"is_preprint":false},{"year":2017,"finding":"Lipid-exposed residues in the transmembrane domain (TMD) of GluA2 are critical for CNIH3 function and complex stability. Mutating these residues had opposite effects on gating modulation when comparing CNIH3- and stargazin-bound AMPARs: a GluA2-A793F mutation destabilized the AMPAR-CNIH3 complex in detergent but produced gain-of-function gating in the membrane, while stabilizing the AMPAR-stargazin complex with diminished gating modulation. Both extracellular and TMD elements contribute independently to CNIH3-mediated gating modulation.","method":"Site-directed mutagenesis of AMPAR TMD, electrophysiology, detergent stability assays, co-immunoprecipitation","journal":"The Journal of Physiology","confidence":"High","confidence_rationale":"Tier 1 — reconstitution with mutagenesis and multiple functional readouts identifying the TMD interaction surface","pmids":["28815591"],"is_preprint":false},{"year":2012,"finding":"CNIH-2 serves an evolutionarily conserved role as a cargo exporter from the endoplasmic reticulum, cycling between ER and Golgi. Interaction with GluA subunits recruits CNIH-2 to the cell surface, with GluAs commandeering CNIH-2 from the early secretory pathway for use as an auxiliary subunit. This ER-to-Golgi cycling is COPII-dependent.","method":"Live-cell imaging, subcellular fractionation, co-immunoprecipitation, heterologous cell expression","journal":"PloS One","confidence":"Medium","confidence_rationale":"Tier 2 — multiple methods establishing localization and functional consequence, but focused on CNIH-2; CNIH-3 role in ER export inferred by extension","pmids":["22292017"],"is_preprint":false},{"year":2023,"finding":"CNIH-3 modulation of AMPAR gating is unaffected by alternative splicing of the flip/flop cassette, in contrast to TARP γ2. CNIH-3 slows receptor deactivation from the outset of current decay, consistent with structural evidence showing its contact at the level of the pore, whereas TARP γ2 acts via the KGK site of the ligand-binding domain to slow onset of desensitization.","method":"Electrophysiology in heterologous cells with flip/flop splice variant constructs and auxiliary subunit co-expression","journal":"The Journal of Neuroscience","confidence":"Medium","confidence_rationale":"Tier 2 — functional dissection with defined constructs establishing mechanistic distinction, single lab","pmids":["36931708"],"is_preprint":false},{"year":2023,"finding":"CNIH-3 only weakly enhances GluA1 tetramerization (unlike CNIH-2 which enhances both GluA1 and GluA2 tetramerization), revealing subunit-specific actions of CNIH-3 in AMPAR biogenesis. The tetramerization-enhancing effect of CNIH-2 is mainly mediated by interactions with the transmembrane domain of the receptor.","method":"Biochemical tetramerization assay, surface expression measurements, co-immunoprecipitation in heterologous cells","journal":"The Journal of Biological Chemistry","confidence":"Medium","confidence_rationale":"Tier 2 — defined biochemical assay with receptor subunit-specific outcomes, single lab","pmids":["37673338"],"is_preprint":false},{"year":2021,"finding":"CNIH3 overexpression in the dorsal hippocampus improved short-term spatial memory selectively in female mice. CNIH3 knockout in female mice caused reduced dorsal hippocampal synapse density, enhanced expression of GluA2-containing (calcium-impermeable) AMPAR subunits in synaptosomes, and attenuated long-term potentiation maintenance; male Cnih3 knockouts were unaffected. These effects were most pronounced during the metestrus phase of the estrous cycle.","method":"Cnih3 knockout mice, viral overexpression, behavioral assays, synaptosome immunoblotting, LTP electrophysiology, super-resolution imaging (SEQUIN)","journal":"Biological Psychiatry","confidence":"Medium","confidence_rationale":"Tier 2 — KO/OE with multiple orthogonal phenotypic readouts and defined molecular mechanism (AMPAR subunit composition)","pmids":["34548146"],"is_preprint":false},{"year":2026,"finding":"Native calcium-permeable cerebellar AMPARs containing GluA1 and GluA4 associate primarily with CNIH3, with GluA4 occupying the B/D positions and GluA1 the A/C positions. Cryo-EM structures of the GluA1/GluA4-CNIH3 complex in resting, active, and desensitized states reveal conformational transitions underlying gating; during desensitization the receptor adopts a pseudo-4-fold configuration of the ligand-binding domain layer.","method":"Native AMPAR purification with subunit-specific antibodies, cryo-EM structural determination in multiple functional states","journal":"Cell Research","confidence":"High","confidence_rationale":"Tier 1 — cryo-EM structures of native complex in multiple functional states with subunit composition determination","pmids":["41840198"],"is_preprint":false},{"year":2013,"finding":"CNIH-2 and CNIH-3 are expressed in developing rat brain with maximum expression early after birth, declining toward adulthood, reciprocal to GluA1-4 expression. Despite this, the ratio of CNIH-2/3 complexed with GluAs remains constant throughout development, with excess AMPAR-free CNIH-2/3 early in development serving the ancestral cargo export role, while their role as AMPAR auxiliary subunits increases with maturation.","method":"RT-PCR, immunoblotting, co-immunoprecipitation across developmental time points in rat brain","journal":"Molecular and Cellular Neurosciences","confidence":"Medium","confidence_rationale":"Tier 2-3 — developmental co-IP time course with defined functional interpretation, single lab","pmids":["23403072"],"is_preprint":false},{"year":2025,"finding":"Cnih3 deletion in mice moderately impaired spatial memory, reward-cue association, and reversal learning, and blunted fentanyl intake during intravenous self-administration. Cnih3 deletion also impaired fentanyl-cue association, linking CNIH3's role in AMPAR subunit composition and kinetics to opioid-related learning and memory processes.","method":"Cnih3 knockout mice, behavioral assays (spatial memory, IVSA), principal component analysis","journal":"bioRxiv","confidence":"Medium","confidence_rationale":"Tier 2 — KO with multiple behavioral phenotypes and defined molecular context, but preprint","pmids":["41292766"],"is_preprint":true}],"current_model":"CNIH3 is an AMPA receptor auxiliary subunit that, as revealed by cryo-EM structures, contains four membrane-spanning helices (not an extracellular domain as previously predicted) and contacts the AMPAR at the transmembrane domain and ligand-binding domain; it slows AMPAR deactivation and desensitization, promotes surface trafficking of GluA1-containing (GluA1A2) heteromers in the hippocampus via interplay with TARP γ-8, and in native cerebellar calcium-permeable AMPARs associates predominantly with GluA1/GluA4 complexes, while also playing an ancestrally conserved COPII-dependent ER cargo export role that GluA subunits co-opt to traffic the receptor to the cell surface."},"narrative":{"teleology":[{"year":2012,"claim":"Establishing that CNIH3 directly modulates AMPAR gating answered whether cornichon homologs function as bona fide auxiliary subunits rather than merely trafficking factors, demonstrating that CNIH3 slows deactivation and desensitization of both calcium-permeable and calcium-impermeable AMPARs and enhances conductance and glutamate sensitivity.","evidence":"Electrophysiology in heterologous cells and native oligodendrocyte precursors with CNIH-3 co-expression/overexpression","pmids":["22815494"],"confidence":"High","gaps":["Structural basis of the CNIH3–AMPAR interaction unknown at this stage","In vivo requirement for CNIH3 at synapses not yet tested","Whether CNIH3 gating modulation differs mechanistically from TARPs was unresolved"]},{"year":2012,"claim":"Demonstrating that CNIH-2 cycles between ER and Golgi in a COPII-dependent manner and is recruited to the surface by GluA subunits established a dual-function model: an ancestral ER cargo export role co-opted by AMPARs for surface trafficking.","evidence":"Live-cell imaging, subcellular fractionation, and co-immunoprecipitation in heterologous cells (focused on CNIH-2)","pmids":["22292017"],"confidence":"Medium","gaps":["Direct demonstration of COPII-dependent cycling for CNIH-3 specifically was not performed","Identity of non-AMPAR cargo clients of CNIH3 unknown","Mechanism by which GluA subunits redirect CNIH from the secretory pathway not defined"]},{"year":2013,"claim":"Conditional knockout of CNIH-2/CNIH-3 in hippocampus revealed that these proteins are essential for surface expression of GluA1-containing AMPARs at synapses, with TARP γ-8 gating the selectivity for GluA1 subunits — resolving a key question about whether CNIHs have subunit-selective roles in vivo.","evidence":"Conditional KO mice, electrophysiology, surface biotinylation, co-immunoprecipitation in hippocampal neurons","pmids":["23522044"],"confidence":"High","gaps":["Individual contributions of CNIH-2 vs. CNIH-3 not separated in this double KO","Mechanism by which TARP γ-8 prevents CNIH association with non-GluA1 subunits unknown","Behavioral consequences of CNIH loss not assessed"]},{"year":2013,"claim":"Developmental profiling showed that CNIH-2/3 are most abundant early postnatally and that excess AMPAR-free CNIH early in life serves the ancestral cargo export role, while the fraction complexed with AMPARs remains constant — establishing a developmental switch in CNIH function.","evidence":"RT-PCR, immunoblotting, co-immunoprecipitation across developmental time points in rat brain","pmids":["23403072"],"confidence":"Medium","gaps":["Non-AMPAR cargo substrates during early development not identified","Whether the developmental ratio is regulated by specific signals is unknown"]},{"year":2014,"claim":"Identification of conserved membrane-proximal residues and the extracellular loop of CNIH-3 as critical for both AMPAR binding and gating modulation — with the AMPAR ligand-binding domain as the principal contact — resolved how CNIH-3 physically engages the receptor and showed that binding and modulation are separable.","evidence":"Single-particle EM, peptide array screening, in vitro mutagenesis, electrophysiology","pmids":["25186755"],"confidence":"High","gaps":["High-resolution atomic model of the interface not yet available","Role of surrounding lipids in the interaction undefined","Whether the separation-of-function mutant has distinct in vivo effects untested"]},{"year":2017,"claim":"Demonstrating that lipid-exposed GluA2 transmembrane residues differentially affect CNIH3 vs. stargazin complex stability and gating established that the AMPAR TMD is a shared but mechanistically distinct interaction surface for different auxiliary subunit classes.","evidence":"Site-directed mutagenesis of GluA2 TMD, electrophysiology, detergent stability assays","pmids":["28815591"],"confidence":"High","gaps":["How TMD and extracellular contacts cooperate quantitatively in modulation unresolved","Whether lipid environment tunes the TMD interaction in vivo not addressed"]},{"year":2019,"claim":"Cryo-EM structures definitively resolved CNIH3 membrane topology as four transmembrane helices (correcting the predicted single-pass topology) and revealed the complete protein–protein interaction interface including surrounding lipids, providing the atomic framework for understanding gating modulation.","evidence":"High-resolution cryo-EM of AMPAR–CNIH3 complex","pmids":["31806817"],"confidence":"High","gaps":["Structures captured in limited conformational states","Contribution of individual lipid species to complex stability not functionally tested","How TARP and CNIH co-occupy the same receptor simultaneously remained unresolved"]},{"year":2021,"claim":"CNIH3 knockout in female mice revealed sex-specific roles in hippocampal synapse density, AMPAR subunit composition, LTP maintenance, and spatial memory, establishing that CNIH3 shapes synaptic plasticity and cognition in a sex- and estrous-cycle-dependent manner.","evidence":"Cnih3 KO and viral overexpression in mice, behavioral assays, synaptosome immunoblotting, LTP recording, super-resolution imaging","pmids":["34548146"],"confidence":"Medium","gaps":["Molecular basis for the sex specificity (hormonal regulation of CNIH3 expression or function) not identified","Whether CNIH2 compensates differently in males vs. females unknown","Single study — replication of sex-specific phenotype needed"]},{"year":2023,"claim":"Showing that CNIH-3 modulation is insensitive to flip/flop splicing and acts from the onset of current decay (consistent with pore-level contact) distinguished its gating mechanism from TARPs, which act via the KGK site on the ligand-binding domain.","evidence":"Electrophysiology with flip/flop splice variant constructs and auxiliary subunit co-expression in heterologous cells","pmids":["36931708"],"confidence":"Medium","gaps":["Structural validation of distinct CNIH3 vs. TARP conformational effects on the pore not yet available","In vivo relevance of flip/flop-independent modulation untested"]},{"year":2023,"claim":"Revealing that CNIH-3 only weakly enhances GluA1 tetramerization (unlike CNIH-2) uncovered subunit-specific differences between the two cornichon paralogs in receptor biogenesis, not just trafficking or gating.","evidence":"Biochemical tetramerization assay, surface expression measurements, co-immunoprecipitation in heterologous cells","pmids":["37673338"],"confidence":"Medium","gaps":["Structural basis for differential tetramerization enhancement between CNIH-2 and CNIH-3 unknown","Whether weak tetramerization activity of CNIH-3 matters in vivo not tested"]},{"year":2026,"claim":"Cryo-EM of native cerebellar calcium-permeable AMPARs revealed that CNIH3 preferentially associates with GluA1/GluA4 heteromers and captured conformational transitions across resting, active, and desensitized states including a pseudo-4-fold LBD configuration during desensitization — providing the first native-complex structural view of CNIH3 function.","evidence":"Native AMPAR purification with subunit-specific antibodies, cryo-EM in multiple functional states","pmids":["41840198"],"confidence":"High","gaps":["How CNIH3 preference for GluA1/GluA4 over other subunit combinations is determined molecularly not resolved","Dynamic transitions between states not captured in time-resolved manner","Whether the pseudo-4-fold desensitized configuration has unique functional consequences untested"]},{"year":null,"claim":"It remains unknown how CNIH3 and TARPs co-assemble on the same AMPAR complex, what signals drive the sex-specific synaptic phenotypes of CNIH3 loss, and whether CNIH3 retains non-AMPAR cargo clients in the mature brain.","evidence":"","pmids":[],"confidence":"Low","gaps":["Structural basis for simultaneous CNIH3–TARP occupancy of a single AMPAR tetramer unresolved","Hormonal or transcriptional mechanisms underlying sex-dependent CNIH3 function unknown","Non-AMPAR cargo substrates of CNIH3 not identified in any system"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0098772","term_label":"molecular function regulator activity","supporting_discovery_ids":[0,2,3,4,6]},{"term_id":"GO:0140104","term_label":"molecular carrier activity","supporting_discovery_ids":[5,10]}],"localization":[{"term_id":"GO:0005886","term_label":"plasma membrane","supporting_discovery_ids":[1,5]},{"term_id":"GO:0005783","term_label":"endoplasmic reticulum","supporting_discovery_ids":[5,10]}],"pathway":[{"term_id":"R-HSA-112316","term_label":"Neuronal System","supporting_discovery_ids":[1,2,8,9]},{"term_id":"R-HSA-9609507","term_label":"Protein localization","supporting_discovery_ids":[1,5,10]}],"complexes":["AMPAR-CNIH3 complex","GluA1/GluA4-CNIH3 cerebellar complex"],"partners":["GRIA1","GRIA2","GRIA4","CACNG8","CNIH2"],"other_free_text":[]},"mechanistic_narrative":"CNIH3 is an auxiliary subunit of AMPA-type ionotropic glutamate receptors (AMPARs) that modulates receptor gating, subunit composition, and surface trafficking in the brain. Cryo-EM structures show CNIH3 contains four transmembrane helices that contact the AMPAR transmembrane domain and ligand-binding domain, slowing deactivation and desensitization independently of flip/flop alternative splicing [PMID:31806817, PMID:36931708]. In the hippocampus, CNIH3 cooperates with TARP γ-8 to selectively promote surface expression of GluA1-containing heteromeric AMPARs, and its loss shifts synaptic AMPAR composition toward GluA2A3 heteromers, reducing synaptic transmission and impairing long-term potentiation in a sex-dependent manner [PMID:23522044, PMID:34548146]. In the cerebellum, CNIH3 associates with native calcium-permeable GluA1/GluA4 complexes, and beyond its role as a gating modulator, CNIH3 shares an ancestrally conserved COPII-dependent ER cargo export function that GluA subunits co-opt for forward trafficking [PMID:41840198, PMID:22292017]."},"prefetch_data":{"uniprot":{"accession":"Q8TBE1","full_name":"Protein cornichon homolog 3","aliases":["Cornichon family AMPA receptor auxiliary protein 3"],"length_aa":160,"mass_kda":19.0,"function":"Regulates the trafficking and gating properties of AMPA-selective glutamate receptors (AMPARs). Promotes their targeting to the cell membrane and synapses and modulates their gating properties by regulating their rates of activation, deactivation and desensitization","subcellular_location":"Postsynaptic cell membrane","url":"https://www.uniprot.org/uniprotkb/Q8TBE1/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/CNIH3","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/CNIH3","total_profiled":1310},"omim":[{"mim_id":"611288","title":"CORNICHON FAMILY AMPA RECEPTOR AUXILIARY PROTEIN 2; CNIH2","url":"https://www.omim.org/entry/611288"},{"mim_id":"611287","title":"CORNICHON FAMILY AMPA RECEPTOR AUXILIARY PROTEIN 1; CNIH1","url":"https://www.omim.org/entry/611287"},{"mim_id":"138248","title":"GLUTAMATE RECEPTOR, IONOTROPIC, AMPA 1; GRIA1","url":"https://www.omim.org/entry/138248"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"","locations":[],"tissue_specificity":"Group enriched","tissue_distribution":"Detected in some","driving_tissues":[{"tissue":"brain","ntpm":10.9},{"tissue":"pancreas","ntpm":7.4}],"url":"https://www.proteinatlas.org/search/CNIH3"},"hgnc":{"alias_symbol":["FLJ38993","CNIH-3"],"prev_symbol":[]},"alphafold":{"accession":"Q8TBE1","domains":[{"cath_id":"-","chopping":"4-158","consensus_level":"high","plddt":85.0114,"start":4,"end":158}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q8TBE1","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q8TBE1-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q8TBE1-F1-predicted_aligned_error_v6.png","plddt_mean":84.5},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=CNIH3","jax_strain_url":"https://www.jax.org/strain/search?query=CNIH3"},"sequence":{"accession":"Q8TBE1","fasta_url":"https://rest.uniprot.org/uniprotkb/Q8TBE1.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q8TBE1/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q8TBE1"}},"corpus_meta":[{"pmid":"23522044","id":"PMC_23522044","title":"Cornichon proteins determine the subunit composition of synaptic AMPA receptors.","date":"2013","source":"Neuron","url":"https://pubmed.ncbi.nlm.nih.gov/23522044","citation_count":126,"is_preprint":false},{"pmid":"30118972","id":"PMC_30118972","title":"A review of opioid addiction genetics.","date":"2018","source":"Current opinion in psychology","url":"https://pubmed.ncbi.nlm.nih.gov/30118972","citation_count":89,"is_preprint":false},{"pmid":"22815494","id":"PMC_22815494","title":"Cornichons modify channel properties of recombinant and glial AMPA receptors.","date":"2012","source":"The Journal of neuroscience : the official journal of the Society for Neuroscience","url":"https://pubmed.ncbi.nlm.nih.gov/22815494","citation_count":86,"is_preprint":false},{"pmid":"23696874","id":"PMC_23696874","title":"Detecting loci under recent positive selection in dairy and beef cattle by combining different genome-wide scan methods.","date":"2013","source":"PloS one","url":"https://pubmed.ncbi.nlm.nih.gov/23696874","citation_count":76,"is_preprint":false},{"pmid":"31806817","id":"PMC_31806817","title":"Structures of the AMPA receptor in complex with its auxiliary subunit cornichon.","date":"2019","source":"Science (New York, N.Y.)","url":"https://pubmed.ncbi.nlm.nih.gov/31806817","citation_count":74,"is_preprint":false},{"pmid":"29302220","id":"PMC_29302220","title":"A brief review of the genetics and pharmacogenetics of opioid use disorders.","date":"2017","source":"Dialogues in clinical neuroscience","url":"https://pubmed.ncbi.nlm.nih.gov/29302220","citation_count":40,"is_preprint":false},{"pmid":"22292017","id":"PMC_22292017","title":"AMPA receptors commandeer an ancient cargo exporter for use as an auxiliary subunit for signaling.","date":"2012","source":"PloS one","url":"https://pubmed.ncbi.nlm.nih.gov/22292017","citation_count":38,"is_preprint":false},{"pmid":"28815591","id":"PMC_28815591","title":"Engineering defined membrane-embedded elements of AMPA receptor induces opposing gating modulation by cornichon 3 and stargazin.","date":"2017","source":"The Journal of physiology","url":"https://pubmed.ncbi.nlm.nih.gov/28815591","citation_count":32,"is_preprint":false},{"pmid":"34621669","id":"PMC_34621669","title":"Identification of Gender-Specific Molecular Differences in Glioblastoma (GBM) and Low-Grade Glioma (LGG) by the Analysis of Large Transcriptomic and Epigenomic Datasets.","date":"2021","source":"Frontiers in oncology","url":"https://pubmed.ncbi.nlm.nih.gov/34621669","citation_count":32,"is_preprint":false},{"pmid":"25186755","id":"PMC_25186755","title":"Molecular dissection of the interaction between the AMPA receptor and cornichon homolog-3.","date":"2014","source":"The Journal of neuroscience : the official journal of the Society for Neuroscience","url":"https://pubmed.ncbi.nlm.nih.gov/25186755","citation_count":29,"is_preprint":false},{"pmid":"31081034","id":"PMC_31081034","title":"Structural basis for preferential binding of human TCF4 to DNA containing 5-carboxylcytosine.","date":"2019","source":"Nucleic acids research","url":"https://pubmed.ncbi.nlm.nih.gov/31081034","citation_count":27,"is_preprint":false},{"pmid":"28358902","id":"PMC_28358902","title":"Screening for AMPA receptor auxiliary subunit specific modulators.","date":"2017","source":"PloS one","url":"https://pubmed.ncbi.nlm.nih.gov/28358902","citation_count":20,"is_preprint":false},{"pmid":"23103966","id":"PMC_23103966","title":"Upregulation of cornichon transcripts in the dorsolateral prefrontal cortex in schizophrenia.","date":"2012","source":"Neuroreport","url":"https://pubmed.ncbi.nlm.nih.gov/23103966","citation_count":20,"is_preprint":false},{"pmid":"23426437","id":"PMC_23426437","title":"Auxiliary subunits provide new insights into regulation of AMPA receptor trafficking.","date":"2013","source":"Journal of biochemistry","url":"https://pubmed.ncbi.nlm.nih.gov/23426437","citation_count":17,"is_preprint":false},{"pmid":"34548146","id":"PMC_34548146","title":"Sex Differences in the Role of CNIH3 on Spatial Memory and Synaptic Plasticity.","date":"2021","source":"Biological psychiatry","url":"https://pubmed.ncbi.nlm.nih.gov/34548146","citation_count":15,"is_preprint":false},{"pmid":"23403072","id":"PMC_23403072","title":"Ontogeny repeats the phylogenetic recruitment of the cargo exporter cornichon into AMPA receptor signaling complexes.","date":"2013","source":"Molecular and cellular neurosciences","url":"https://pubmed.ncbi.nlm.nih.gov/23403072","citation_count":13,"is_preprint":false},{"pmid":"38987777","id":"PMC_38987777","title":"Comprehensive analysis of hub genes associated with cisplatin-resistance in ovarian cancer and screening of therapeutic drugs through bioinformatics and experimental validation.","date":"2024","source":"Journal of ovarian research","url":"https://pubmed.ncbi.nlm.nih.gov/38987777","citation_count":9,"is_preprint":false},{"pmid":"25792422","id":"PMC_25792422","title":"Prolonged glutamate excitotoxicity increases GluR1 immunoreactivity but decreases mRNA of GluR1 and associated regulatory proteins in dissociated rat retinae in vitro.","date":"2015","source":"Biochimie","url":"https://pubmed.ncbi.nlm.nih.gov/25792422","citation_count":9,"is_preprint":false},{"pmid":"40240269","id":"PMC_40240269","title":"Genome-wide association meta-analyses of drug-resistant epilepsy.","date":"2025","source":"EBioMedicine","url":"https://pubmed.ncbi.nlm.nih.gov/40240269","citation_count":8,"is_preprint":false},{"pmid":"38457199","id":"PMC_38457199","title":"Comparison of genomic alterations in Epstein-Barr virus-positive and Epstein-Barr virus-negative diffuse large B-cell lymphoma.","date":"2024","source":"Cancer medicine","url":"https://pubmed.ncbi.nlm.nih.gov/38457199","citation_count":8,"is_preprint":false},{"pmid":"37673338","id":"PMC_37673338","title":"Differential regulation of tetramerization of the AMPA receptor glutamate-gated ion channel by auxiliary subunits.","date":"2023","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/37673338","citation_count":6,"is_preprint":false},{"pmid":"36931708","id":"PMC_36931708","title":"Alternative Splicing of the Flip/Flop Cassette and TARP Auxiliary Subunits Engage in a Privileged Relationship That Fine-Tunes AMPA Receptor Gating.","date":"2023","source":"The Journal of neuroscience : the official journal of the Society for Neuroscience","url":"https://pubmed.ncbi.nlm.nih.gov/36931708","citation_count":6,"is_preprint":false},{"pmid":"30967136","id":"PMC_30967136","title":"Novel potential causative genes in carotid paragangliomas.","date":"2019","source":"BMC medical genetics","url":"https://pubmed.ncbi.nlm.nih.gov/30967136","citation_count":6,"is_preprint":false},{"pmid":"36230901","id":"PMC_36230901","title":"Locus-Specific Enrichment Analysis of 5-Hydroxymethylcytosine Reveals Novel Genes Associated with Breast Carcinogenesis.","date":"2022","source":"Cells","url":"https://pubmed.ncbi.nlm.nih.gov/36230901","citation_count":6,"is_preprint":false},{"pmid":"36849260","id":"PMC_36849260","title":"Cnih3 Deletion Dysregulates Dorsal Hippocampal Transcription across the Estrous Cycle.","date":"2023","source":"eNeuro","url":"https://pubmed.ncbi.nlm.nih.gov/36849260","citation_count":4,"is_preprint":false},{"pmid":"38655066","id":"PMC_38655066","title":"Transcriptomic profile of premature ovarian insufficiency with RNA-sequencing.","date":"2024","source":"Frontiers in cell and developmental biology","url":"https://pubmed.ncbi.nlm.nih.gov/38655066","citation_count":4,"is_preprint":false},{"pmid":"41840198","id":"PMC_41840198","title":"Assembly and gating mechanism of native AMPA receptors from the cerebellum.","date":"2026","source":"Cell research","url":"https://pubmed.ncbi.nlm.nih.gov/41840198","citation_count":3,"is_preprint":false},{"pmid":"38836370","id":"PMC_38836370","title":"The Role of Cornichons in the Biogenesis and Functioning of Monovalent-Cation Transport Systems.","date":"2024","source":"Physiological research","url":"https://pubmed.ncbi.nlm.nih.gov/38836370","citation_count":2,"is_preprint":false},{"pmid":"36798164","id":"PMC_36798164","title":"Differential regulation of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid (AMPA) receptor tetramerization by auxiliary subunits.","date":"2023","source":"bioRxiv : the preprint server for biology","url":"https://pubmed.ncbi.nlm.nih.gov/36798164","citation_count":1,"is_preprint":false},{"pmid":"41292766","id":"PMC_41292766","title":"Cornichon Homolog-3 (Cnih3) deletion impairs spatial memory, reward-cue association, and fentanyl self-administration behavior.","date":"2025","source":"bioRxiv : the preprint server for biology","url":"https://pubmed.ncbi.nlm.nih.gov/41292766","citation_count":0,"is_preprint":false},{"pmid":"40771158","id":"PMC_40771158","title":"Unravelling the genetic complexity of drug-resistant epilepsy: a critical narrative review.","date":"2025","source":"Expert review of clinical pharmacology","url":"https://pubmed.ncbi.nlm.nih.gov/40771158","citation_count":0,"is_preprint":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":18298,"output_tokens":3264,"usd":0.051927},"stage2":{"model":"claude-opus-4-6","input_tokens":6617,"output_tokens":3208,"usd":0.169928},"total_usd":0.221855,"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\": 2019,\n      \"finding\": \"Cryo-EM structures of AMPAR in complex with CNIH3 revealed that CNIH3 lacks an extracellular domain and instead contains four membrane-spanning helices, contrary to its predicted membrane topology. The protein-protein interaction interface between CNIH3 and the AMPAR that dictates channel modulation was identified, along with surrounding lipids.\",\n      \"method\": \"High-resolution cryo-electron microscopy structural determination\",\n      \"journal\": \"Science\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 — cryo-EM structure with functional validation, single rigorous paper resolving topology and interaction interface\",\n      \"pmids\": [\"31806817\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"Using CNIH-2 and CNIH-3 conditional knockout mice, CNIH-2/-3 were shown to be required for surface expression of GluA1-containing AMPARs (GluA1A2 heteromers) at hippocampal synapses. Loss of CNIHs resulted in a profound reduction of AMPAR synaptic transmission, leaving only a residual pool of GluA2A3 heteromers. The selective effect of CNIHs on GluA1 is mediated via TARP γ-8, which prevents functional association of CNIHs with non-GluA1 subunits.\",\n      \"method\": \"Conditional knockout mice, electrophysiology, surface biotinylation, co-immunoprecipitation\",\n      \"journal\": \"Neuron\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — conditional KO with specific cellular phenotype, multiple orthogonal methods, highly cited\",\n      \"pmids\": [\"23522044\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"CNIH-3 (but not CNIH-1) slows the deactivation and desensitization of both GluA2-containing calcium-impermeable and GluA2-lacking calcium-permeable AMPARs expressed in heterologous cells. CNIH-2 and CNIH-3 also enhanced glutamate sensitivity, single-channel conductance, and calcium permeability of calcium-permeable AMPARs, while decreasing their block by intracellular polyamines. Overexpression of CNIH-3 in oligodendrocyte precursor cells markedly slowed AMPAR desensitization.\",\n      \"method\": \"Electrophysiology in tsA201 cells and native glial cells, overexpression, antibody surface labeling\",\n      \"journal\": \"The Journal of Neuroscience\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 — in vitro reconstitution with electrophysiological assays in heterologous and native cells, replicated across conditions\",\n      \"pmids\": [\"22815494\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"CNIH-3 forms a stable complex with tetrameric AMPARs and contributes to the transmembrane density in single-particle electron microscopy structures. Peptide array-based screening and in vitro mutagenesis identified two clusters of conserved membrane-proximal residues in CNIHs that contribute to AMPAR binding. Residues in the extracellular loop of CNIH-2/3 absent in CNIH-1/4 are critical for both AMPAR interaction and gating modulation. The AMPAR ligand-binding domain (and possibly a linker connecting it to the fourth membrane-spanning segment) is the principal contact point with the CNIH-3 extracellular loop. A mutant CNIH-3 was identified that preserves AMPAR binding but has attenuated gating modulation.\",\n      \"method\": \"Single-particle electron microscopy, peptide array screening, in vitro mutagenesis, co-immunoprecipitation, electrophysiology\",\n      \"journal\": \"The Journal of Neuroscience\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 — multiple orthogonal methods including structure, mutagenesis, and functional assays in single study\",\n      \"pmids\": [\"25186755\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"Lipid-exposed residues in the transmembrane domain (TMD) of GluA2 are critical for CNIH3 function and complex stability. Mutating these residues had opposite effects on gating modulation when comparing CNIH3- and stargazin-bound AMPARs: a GluA2-A793F mutation destabilized the AMPAR-CNIH3 complex in detergent but produced gain-of-function gating in the membrane, while stabilizing the AMPAR-stargazin complex with diminished gating modulation. Both extracellular and TMD elements contribute independently to CNIH3-mediated gating modulation.\",\n      \"method\": \"Site-directed mutagenesis of AMPAR TMD, electrophysiology, detergent stability assays, co-immunoprecipitation\",\n      \"journal\": \"The Journal of Physiology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 — reconstitution with mutagenesis and multiple functional readouts identifying the TMD interaction surface\",\n      \"pmids\": [\"28815591\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"CNIH-2 serves an evolutionarily conserved role as a cargo exporter from the endoplasmic reticulum, cycling between ER and Golgi. Interaction with GluA subunits recruits CNIH-2 to the cell surface, with GluAs commandeering CNIH-2 from the early secretory pathway for use as an auxiliary subunit. This ER-to-Golgi cycling is COPII-dependent.\",\n      \"method\": \"Live-cell imaging, subcellular fractionation, co-immunoprecipitation, heterologous cell expression\",\n      \"journal\": \"PloS One\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — multiple methods establishing localization and functional consequence, but focused on CNIH-2; CNIH-3 role in ER export inferred by extension\",\n      \"pmids\": [\"22292017\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"CNIH-3 modulation of AMPAR gating is unaffected by alternative splicing of the flip/flop cassette, in contrast to TARP γ2. CNIH-3 slows receptor deactivation from the outset of current decay, consistent with structural evidence showing its contact at the level of the pore, whereas TARP γ2 acts via the KGK site of the ligand-binding domain to slow onset of desensitization.\",\n      \"method\": \"Electrophysiology in heterologous cells with flip/flop splice variant constructs and auxiliary subunit co-expression\",\n      \"journal\": \"The Journal of Neuroscience\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — functional dissection with defined constructs establishing mechanistic distinction, single lab\",\n      \"pmids\": [\"36931708\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"CNIH-3 only weakly enhances GluA1 tetramerization (unlike CNIH-2 which enhances both GluA1 and GluA2 tetramerization), revealing subunit-specific actions of CNIH-3 in AMPAR biogenesis. The tetramerization-enhancing effect of CNIH-2 is mainly mediated by interactions with the transmembrane domain of the receptor.\",\n      \"method\": \"Biochemical tetramerization assay, surface expression measurements, co-immunoprecipitation in heterologous cells\",\n      \"journal\": \"The Journal of Biological Chemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — defined biochemical assay with receptor subunit-specific outcomes, single lab\",\n      \"pmids\": [\"37673338\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"CNIH3 overexpression in the dorsal hippocampus improved short-term spatial memory selectively in female mice. CNIH3 knockout in female mice caused reduced dorsal hippocampal synapse density, enhanced expression of GluA2-containing (calcium-impermeable) AMPAR subunits in synaptosomes, and attenuated long-term potentiation maintenance; male Cnih3 knockouts were unaffected. These effects were most pronounced during the metestrus phase of the estrous cycle.\",\n      \"method\": \"Cnih3 knockout mice, viral overexpression, behavioral assays, synaptosome immunoblotting, LTP electrophysiology, super-resolution imaging (SEQUIN)\",\n      \"journal\": \"Biological Psychiatry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — KO/OE with multiple orthogonal phenotypic readouts and defined molecular mechanism (AMPAR subunit composition)\",\n      \"pmids\": [\"34548146\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2026,\n      \"finding\": \"Native calcium-permeable cerebellar AMPARs containing GluA1 and GluA4 associate primarily with CNIH3, with GluA4 occupying the B/D positions and GluA1 the A/C positions. Cryo-EM structures of the GluA1/GluA4-CNIH3 complex in resting, active, and desensitized states reveal conformational transitions underlying gating; during desensitization the receptor adopts a pseudo-4-fold configuration of the ligand-binding domain layer.\",\n      \"method\": \"Native AMPAR purification with subunit-specific antibodies, cryo-EM structural determination in multiple functional states\",\n      \"journal\": \"Cell Research\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 — cryo-EM structures of native complex in multiple functional states with subunit composition determination\",\n      \"pmids\": [\"41840198\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"CNIH-2 and CNIH-3 are expressed in developing rat brain with maximum expression early after birth, declining toward adulthood, reciprocal to GluA1-4 expression. Despite this, the ratio of CNIH-2/3 complexed with GluAs remains constant throughout development, with excess AMPAR-free CNIH-2/3 early in development serving the ancestral cargo export role, while their role as AMPAR auxiliary subunits increases with maturation.\",\n      \"method\": \"RT-PCR, immunoblotting, co-immunoprecipitation across developmental time points in rat brain\",\n      \"journal\": \"Molecular and Cellular Neurosciences\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2-3 — developmental co-IP time course with defined functional interpretation, single lab\",\n      \"pmids\": [\"23403072\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"Cnih3 deletion in mice moderately impaired spatial memory, reward-cue association, and reversal learning, and blunted fentanyl intake during intravenous self-administration. Cnih3 deletion also impaired fentanyl-cue association, linking CNIH3's role in AMPAR subunit composition and kinetics to opioid-related learning and memory processes.\",\n      \"method\": \"Cnih3 knockout mice, behavioral assays (spatial memory, IVSA), principal component analysis\",\n      \"journal\": \"bioRxiv\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — KO with multiple behavioral phenotypes and defined molecular context, but preprint\",\n      \"pmids\": [\"41292766\"],\n      \"is_preprint\": true\n    }\n  ],\n  \"current_model\": \"CNIH3 is an AMPA receptor auxiliary subunit that, as revealed by cryo-EM structures, contains four membrane-spanning helices (not an extracellular domain as previously predicted) and contacts the AMPAR at the transmembrane domain and ligand-binding domain; it slows AMPAR deactivation and desensitization, promotes surface trafficking of GluA1-containing (GluA1A2) heteromers in the hippocampus via interplay with TARP γ-8, and in native cerebellar calcium-permeable AMPARs associates predominantly with GluA1/GluA4 complexes, while also playing an ancestrally conserved COPII-dependent ER cargo export role that GluA subunits co-opt to traffic the receptor to the cell surface.\"\n}\n```","stage2_raw":"```json\n{\n  \"mechanistic_narrative\": \"CNIH3 is an auxiliary subunit of AMPA-type ionotropic glutamate receptors (AMPARs) that modulates receptor gating, subunit composition, and surface trafficking in the brain. Cryo-EM structures show CNIH3 contains four transmembrane helices that contact the AMPAR transmembrane domain and ligand-binding domain, slowing deactivation and desensitization independently of flip/flop alternative splicing [PMID:31806817, PMID:36931708]. In the hippocampus, CNIH3 cooperates with TARP γ-8 to selectively promote surface expression of GluA1-containing heteromeric AMPARs, and its loss shifts synaptic AMPAR composition toward GluA2A3 heteromers, reducing synaptic transmission and impairing long-term potentiation in a sex-dependent manner [PMID:23522044, PMID:34548146]. In the cerebellum, CNIH3 associates with native calcium-permeable GluA1/GluA4 complexes, and beyond its role as a gating modulator, CNIH3 shares an ancestrally conserved COPII-dependent ER cargo export function that GluA subunits co-opt for forward trafficking [PMID:41840198, PMID:22292017].\",\n  \"teleology\": [\n    {\n      \"year\": 2012,\n      \"claim\": \"Establishing that CNIH3 directly modulates AMPAR gating answered whether cornichon homologs function as bona fide auxiliary subunits rather than merely trafficking factors, demonstrating that CNIH3 slows deactivation and desensitization of both calcium-permeable and calcium-impermeable AMPARs and enhances conductance and glutamate sensitivity.\",\n      \"evidence\": \"Electrophysiology in heterologous cells and native oligodendrocyte precursors with CNIH-3 co-expression/overexpression\",\n      \"pmids\": [\"22815494\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"Structural basis of the CNIH3–AMPAR interaction unknown at this stage\",\n        \"In vivo requirement for CNIH3 at synapses not yet tested\",\n        \"Whether CNIH3 gating modulation differs mechanistically from TARPs was unresolved\"\n      ]\n    },\n    {\n      \"year\": 2012,\n      \"claim\": \"Demonstrating that CNIH-2 cycles between ER and Golgi in a COPII-dependent manner and is recruited to the surface by GluA subunits established a dual-function model: an ancestral ER cargo export role co-opted by AMPARs for surface trafficking.\",\n      \"evidence\": \"Live-cell imaging, subcellular fractionation, and co-immunoprecipitation in heterologous cells (focused on CNIH-2)\",\n      \"pmids\": [\"22292017\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Direct demonstration of COPII-dependent cycling for CNIH-3 specifically was not performed\",\n        \"Identity of non-AMPAR cargo clients of CNIH3 unknown\",\n        \"Mechanism by which GluA subunits redirect CNIH from the secretory pathway not defined\"\n      ]\n    },\n    {\n      \"year\": 2013,\n      \"claim\": \"Conditional knockout of CNIH-2/CNIH-3 in hippocampus revealed that these proteins are essential for surface expression of GluA1-containing AMPARs at synapses, with TARP γ-8 gating the selectivity for GluA1 subunits — resolving a key question about whether CNIHs have subunit-selective roles in vivo.\",\n      \"evidence\": \"Conditional KO mice, electrophysiology, surface biotinylation, co-immunoprecipitation in hippocampal neurons\",\n      \"pmids\": [\"23522044\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"Individual contributions of CNIH-2 vs. CNIH-3 not separated in this double KO\",\n        \"Mechanism by which TARP γ-8 prevents CNIH association with non-GluA1 subunits unknown\",\n        \"Behavioral consequences of CNIH loss not assessed\"\n      ]\n    },\n    {\n      \"year\": 2013,\n      \"claim\": \"Developmental profiling showed that CNIH-2/3 are most abundant early postnatally and that excess AMPAR-free CNIH early in life serves the ancestral cargo export role, while the fraction complexed with AMPARs remains constant — establishing a developmental switch in CNIH function.\",\n      \"evidence\": \"RT-PCR, immunoblotting, co-immunoprecipitation across developmental time points in rat brain\",\n      \"pmids\": [\"23403072\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Non-AMPAR cargo substrates during early development not identified\",\n        \"Whether the developmental ratio is regulated by specific signals is unknown\"\n      ]\n    },\n    {\n      \"year\": 2014,\n      \"claim\": \"Identification of conserved membrane-proximal residues and the extracellular loop of CNIH-3 as critical for both AMPAR binding and gating modulation — with the AMPAR ligand-binding domain as the principal contact — resolved how CNIH-3 physically engages the receptor and showed that binding and modulation are separable.\",\n      \"evidence\": \"Single-particle EM, peptide array screening, in vitro mutagenesis, electrophysiology\",\n      \"pmids\": [\"25186755\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"High-resolution atomic model of the interface not yet available\",\n        \"Role of surrounding lipids in the interaction undefined\",\n        \"Whether the separation-of-function mutant has distinct in vivo effects untested\"\n      ]\n    },\n    {\n      \"year\": 2017,\n      \"claim\": \"Demonstrating that lipid-exposed GluA2 transmembrane residues differentially affect CNIH3 vs. stargazin complex stability and gating established that the AMPAR TMD is a shared but mechanistically distinct interaction surface for different auxiliary subunit classes.\",\n      \"evidence\": \"Site-directed mutagenesis of GluA2 TMD, electrophysiology, detergent stability assays\",\n      \"pmids\": [\"28815591\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"How TMD and extracellular contacts cooperate quantitatively in modulation unresolved\",\n        \"Whether lipid environment tunes the TMD interaction in vivo not addressed\"\n      ]\n    },\n    {\n      \"year\": 2019,\n      \"claim\": \"Cryo-EM structures definitively resolved CNIH3 membrane topology as four transmembrane helices (correcting the predicted single-pass topology) and revealed the complete protein–protein interaction interface including surrounding lipids, providing the atomic framework for understanding gating modulation.\",\n      \"evidence\": \"High-resolution cryo-EM of AMPAR–CNIH3 complex\",\n      \"pmids\": [\"31806817\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"Structures captured in limited conformational states\",\n        \"Contribution of individual lipid species to complex stability not functionally tested\",\n        \"How TARP and CNIH co-occupy the same receptor simultaneously remained unresolved\"\n      ]\n    },\n    {\n      \"year\": 2021,\n      \"claim\": \"CNIH3 knockout in female mice revealed sex-specific roles in hippocampal synapse density, AMPAR subunit composition, LTP maintenance, and spatial memory, establishing that CNIH3 shapes synaptic plasticity and cognition in a sex- and estrous-cycle-dependent manner.\",\n      \"evidence\": \"Cnih3 KO and viral overexpression in mice, behavioral assays, synaptosome immunoblotting, LTP recording, super-resolution imaging\",\n      \"pmids\": [\"34548146\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Molecular basis for the sex specificity (hormonal regulation of CNIH3 expression or function) not identified\",\n        \"Whether CNIH2 compensates differently in males vs. females unknown\",\n        \"Single study — replication of sex-specific phenotype needed\"\n      ]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"Showing that CNIH-3 modulation is insensitive to flip/flop splicing and acts from the onset of current decay (consistent with pore-level contact) distinguished its gating mechanism from TARPs, which act via the KGK site on the ligand-binding domain.\",\n      \"evidence\": \"Electrophysiology with flip/flop splice variant constructs and auxiliary subunit co-expression in heterologous cells\",\n      \"pmids\": [\"36931708\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Structural validation of distinct CNIH3 vs. TARP conformational effects on the pore not yet available\",\n        \"In vivo relevance of flip/flop-independent modulation untested\"\n      ]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"Revealing that CNIH-3 only weakly enhances GluA1 tetramerization (unlike CNIH-2) uncovered subunit-specific differences between the two cornichon paralogs in receptor biogenesis, not just trafficking or gating.\",\n      \"evidence\": \"Biochemical tetramerization assay, surface expression measurements, co-immunoprecipitation in heterologous cells\",\n      \"pmids\": [\"37673338\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Structural basis for differential tetramerization enhancement between CNIH-2 and CNIH-3 unknown\",\n        \"Whether weak tetramerization activity of CNIH-3 matters in vivo not tested\"\n      ]\n    },\n    {\n      \"year\": 2026,\n      \"claim\": \"Cryo-EM of native cerebellar calcium-permeable AMPARs revealed that CNIH3 preferentially associates with GluA1/GluA4 heteromers and captured conformational transitions across resting, active, and desensitized states including a pseudo-4-fold LBD configuration during desensitization — providing the first native-complex structural view of CNIH3 function.\",\n      \"evidence\": \"Native AMPAR purification with subunit-specific antibodies, cryo-EM in multiple functional states\",\n      \"pmids\": [\"41840198\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"How CNIH3 preference for GluA1/GluA4 over other subunit combinations is determined molecularly not resolved\",\n        \"Dynamic transitions between states not captured in time-resolved manner\",\n        \"Whether the pseudo-4-fold desensitized configuration has unique functional consequences untested\"\n      ]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"It remains unknown how CNIH3 and TARPs co-assemble on the same AMPAR complex, what signals drive the sex-specific synaptic phenotypes of CNIH3 loss, and whether CNIH3 retains non-AMPAR cargo clients in the mature brain.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Low\",\n      \"gaps\": [\n        \"Structural basis for simultaneous CNIH3–TARP occupancy of a single AMPAR tetramer unresolved\",\n        \"Hormonal or transcriptional mechanisms underlying sex-dependent CNIH3 function unknown\",\n        \"Non-AMPAR cargo substrates of CNIH3 not identified in any system\"\n      ]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0098772\", \"supporting_discovery_ids\": [0, 2, 3, 4, 6]},\n      {\"term_id\": \"GO:0140104\", \"supporting_discovery_ids\": [5, 10]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005886\", \"supporting_discovery_ids\": [1, 5]},\n      {\"term_id\": \"GO:0005783\", \"supporting_discovery_ids\": [5, 10]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-112316\", \"supporting_discovery_ids\": [1, 2, 8, 9]},\n      {\"term_id\": \"R-HSA-9609507\", \"supporting_discovery_ids\": [1, 5, 10]}\n    ],\n    \"complexes\": [\n      \"AMPAR-CNIH3 complex\",\n      \"GluA1/GluA4-CNIH3 cerebellar complex\"\n    ],\n    \"partners\": [\n      \"GRIA1\",\n      \"GRIA2\",\n      \"GRIA4\",\n      \"CACNG8\",\n      \"CNIH2\"\n    ],\n    \"other_free_text\": []\n  }\n}\n```"}