{"gene":"LRRC8E","run_date":"2026-06-10T02:59:50","timeline":{"discoveries":[{"year":2004,"finding":"LRRC8E (FLJ23420) was identified as a member of the LRRC8 family, predicted to encode a protein with 16 extracellular leucine-rich repeats but lacking four transmembrane regions present in the other family members, suggesting a distinct structural configuration.","method":"Bioinformatic sequence analysis and predicted structural comparison","journal":"FEBS letters","confidence":"Low","confidence_rationale":"Tier 4 / Weak — computational/bioinformatic prediction only, no functional assay performed","pmids":["15094057"],"is_preprint":false},{"year":2015,"finding":"LRRC8E is a subunit of heteromeric LRRC8 volume-regulated anion channels (VRACs); however, LRRC8E-containing (but not LRRC8D-containing) VRACs do not contribute significantly to cisplatin uptake under isotonic conditions, whereas LRRC8A/LRRC8D channels are the primary mediators of cisplatin transport.","method":"Genetic knockout/knockdown of individual LRRC8 subunits combined with radiotracer and drug uptake assays","journal":"The EMBO journal","confidence":"High","confidence_rationale":"Tier 2 / Strong — genetic ablation with functional readout, replicated across subunits with clear subunit-specificity, published in peer-reviewed journal","pmids":["26530471"],"is_preprint":false},{"year":2016,"finding":"The C-terminal part of the first extracellular loop (EL1) of LRRC8E, specifically two conserved charged residues equivalent to Lys-98 and Asp-100 in LRRC8A, determines voltage-dependent inactivation kinetics and contributes to iodide/chloride selectivity of LRRC8A/E heteromeric VRACs.","method":"Chimera construction between LRRC8C and LRRC8E, point mutagenesis, electrophysiology","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1 / Moderate — in vitro mutagenesis combined with electrophysiological functional validation, multiple mutations tested in a single rigorous study","pmids":["27325695"],"is_preprint":false},{"year":2016,"finding":"Overexpression of LRRC8A alone or together with LRRC8D or LRRC8E in VSOR-deficient KCP-4 cells failed to restore VSOR activity, indicating that LRRC8A/D/E expression alone is not sufficient for channel function and that additional unidentified factors are required.","method":"siRNA knockdown and overexpression in KCP-4 and C127 cells with electrophysiological current measurements","journal":"Channels (Austin, Tex.)","confidence":"Medium","confidence_rationale":"Tier 2 / Weak — clean KO/OE with defined electrophysiological readout, but single lab and single method","pmids":["27764579"],"is_preprint":false},{"year":2017,"finding":"In primary rat astrocytes, LRRC8A/C/E-containing heteromeric VRACs preferentially mediate swelling-activated release of charged organic osmolytes (d-aspartate), while LRRC8A/D channels dominate release of uncharged osmolytes (taurine, myo-inositol). Knockdown of LRRC8C+LRRC8E selectively reduced d-aspartate efflux without major effect on taurine release.","method":"RNAi knockdown of individual LRRC8 subunits combined with radiotracer flux assays in primary rat astrocytes under hypoosmotic challenge","journal":"The Journal of physiology","confidence":"High","confidence_rationale":"Tier 2 / Moderate — RNAi with radiotracer functional assay, multiple subunit combinations tested, orthogonal osmolytes used as readouts","pmids":["28833202"],"is_preprint":false},{"year":2017,"finding":"LRRC8A/LRRC8E heteromeric channels are dramatically activated (>10-fold potentiation) by oxidation of intracellular cysteine residues via chloramine-T or tert-butyl hydroperoxide, in contrast to LRRC8A/LRRC8C and LRRC8A/LRRC8D heteromers which are inhibited by oxidation, demonstrating direct subunit-dependent modulation of VRAC by reactive oxygen species.","method":"Electrophysiology on fluorescently-tagged LRRC8 heteromers expressed in cells, oxidant treatment, comparison with Jurkat T lymphocyte endogenous currents","journal":"The Journal of physiology","confidence":"High","confidence_rationale":"Tier 2 / Moderate — electrophysiological functional assay with multiple oxidants, subunit-specific comparison, corroborated with endogenous currents in Jurkat cells","pmids":["28841766"],"is_preprint":false},{"year":2018,"finding":"The first extracellular loop (EL1) connecting transmembrane domains 1 and 2 of LRRC8E is essential for VRAC activity. Replacing EL1 of LRRC8A with that of LRRC8E in a chimeric construct generates homomeric VRACs with normal volume-dependent regulation. A 25-amino acid sequence unique to the LRRC8A intracellular loop, when inserted into LRRC8E, is sufficient to generate homomeric VRAC activity, and influences anion permeability, rectification, and voltage sensitivity.","method":"Chimera construction and domain-swap experiments between LRRC8A, LRRC8C, LRRC8D, and LRRC8E; electrophysiology","journal":"The Journal of general physiology","confidence":"High","confidence_rationale":"Tier 1 / Moderate — structure-function chimera analysis with electrophysiological validation, multiple chimeras and subunits tested in a single rigorous study","pmids":["29853476"],"is_preprint":false},{"year":2020,"finding":"LRRC8A/LRRC8E-containing VRACs transport cGAMP and cyclic dinucleotides across the plasma membrane, mediating cell-to-cell transfer of cGAMP. Lrrc8e−/− mice exhibited impaired interferon responses and compromised immunity to HSV-1, establishing LRRC8E as a functionally important subunit for cGAMP transport and anti-viral innate immunity.","method":"Biochemical transport assays, electrophysiology, genetic knockout mice (Lrrc8e−/−), viral infection assays (HSV-1), IFN response measurement","journal":"Immunity","confidence":"High","confidence_rationale":"Tier 2 / Strong — multiple orthogonal methods (biochemical, electrophysiological, in vivo genetic), replicated across cell types and validated with in vivo mouse model","pmids":["32277911"],"is_preprint":false},{"year":2020,"finding":"LRRC8A forms complexes with LRRC8C and/or LRRC8E depending on their expression levels to transport cGAMP and other 2'3'-cyclic dinucleotides; in contrast, LRRC8D inhibits cGAMP transport. cGAMP is effluxed or influxed via LRRC8 channels depending on the electrochemical gradient. LRRC8A/C/E channels are key cGAMP transporters in resting primary human vasculature cells and universal human cGAMP transporters when activated.","method":"Genome-wide CRISPR screen, genetic knockout/overexpression, transport assays, electrophysiology in multiple human cell lines and primary cells","journal":"Molecular cell","confidence":"High","confidence_rationale":"Tier 2 / Strong — CRISPR screen plus orthogonal transport and electrophysiological assays, multiple cell types including primary human cells, independently published from different lab than PMID:32277911","pmids":["33171122"],"is_preprint":false},{"year":2021,"finding":"LRRC8A/E-containing VRACs specialized in cGAMP transport can be opened by a protein component in serum under resting (isotonic) conditions; serum depletion ablates tonic LRRC8A/E VRAC activity and decreases cGAMP transport. The plasma membrane-localized form of cGAS (not its DNA-binding or enzymatic activity) enables VRAC activation, and phospholipid PIP2 is instrumental in membrane localization of cGAS and its association with VRACs.","method":"Genetic analyses (cGAS knockouts/mutants), proteinase K and heat treatment of serum, cGAMP transport assays, membrane fractionation","journal":"Journal of immunology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — multiple genetic and biochemical approaches in a single lab, but some mechanistic claims (PIP2 role) lack full reconstitution","pmids":["33827893"],"is_preprint":false},{"year":2022,"finding":"Two intracellular cysteines in the first two leucine-rich repeats of LRRC8E (C424 and C448) are the molecular targets of oxidation. Oxidation likely forms a disulfide bond between these two cysteines, inducing a conformational change that activates LRRC8A/LRRC8E heteromeric channels.","method":"Chimeric and concatemeric LRRC8 constructs, site-directed mutagenesis of specific cysteines, electrophysiology with oxidant treatment","journal":"The Journal of physiology","confidence":"High","confidence_rationale":"Tier 1 / Moderate — mutagenesis of specific residues combined with electrophysiological functional readout, concatemeric strategy to control subunit stoichiometry, multiple oxidants tested","pmids":["35861288"],"is_preprint":false},{"year":2022,"finding":"In the kidney, LRRC8E localizes specifically to intercalated cells of the collecting duct, a distinct localization from other VRAC subunits (LRRC8A, LRRC8B, LRRC8D in basolateral membranes of proximal tubules; LRRC8C exclusively in vascular endothelium). Constitutive deletion of Lrrc8e did not cause proximal tubulopathy (unlike Lrrc8d or Lrrc8a deletion), suggesting LRRC8E plays a distinct renal role.","method":"Epitope-tagged knock-in mice for localization, constitutive knockout mice with histology and urine/serum functional analysis, metabolomics","journal":"Journal of the American Society of Nephrology","confidence":"High","confidence_rationale":"Tier 2 / Strong — direct localization by epitope tagging in vivo combined with genetic knockout phenotypic analysis, multiple subunits compared in parallel","pmids":["35777784"],"is_preprint":false},{"year":2025,"finding":"Disruption of LRRC8E (along with LRRC8B, LRRC8C, or LRRC8D) had no discernible effect on T or B cell development in mice. In subcutaneous tumor models, disruption of LRRC8E in host cells did not impair the cGAMP-mediated anti-tumor immune response, indicating that VRAC-mediated cGAMP transport involving LRRC8E is dispensable for anti-tumor immunity in vivo, which is instead primarily mediated by other transporters.","method":"Genetic knockout mice with selective LRRC8 subunit disruptions, syngeneic subcutaneous tumor models (MC38, B16-F10), serum cytokine measurements, tumor growth assays, flow cytometry of lymphocyte development","journal":"The Journal of biological chemistry","confidence":"Medium","confidence_rationale":"Tier 2 / Weak — clean in vivo genetic knockout with defined phenotypic readout, but single lab and the finding is a negative result for LRRC8E-specific contribution in this context","pmids":["41419196"],"is_preprint":false}],"current_model":"LRRC8E is a non-essential accessory subunit of heteromeric LRRC8 volume-regulated anion channels (VRACs), forming hexameric complexes with the obligatory LRRC8A subunit; LRRC8A/LRRC8E channels preferentially transport charged substrates including cGAMP and cyclic dinucleotides (mediating innate immune signaling), are uniquely activated (>10-fold) by oxidation of two intracellular cysteines (C424 and C448) via disulfide bond formation, and exhibit distinct voltage-dependent inactivation and anion selectivity determined by conserved charged residues in the first extracellular loop; in vivo, LRRC8E localizes specifically to renal intercalated cells and its deletion does not cause the proximal tubulopathy seen with LRRC8A/D loss, while its role in cGAMP-mediated anti-tumor immunity in vivo appears dispensable."},"narrative":{"mechanistic_narrative":"LRRC8E is an accessory subunit of heteromeric LRRC8 volume-regulated anion channels (VRACs), assembling with the obligatory LRRC8A subunit to form channels with subunit-specific transport and gating properties [PMID:26530471, PMID:28833202]. LRRC8A/E channels confer distinct functional signatures: they preferentially mediate swelling-activated efflux of charged organic osmolytes such as d-aspartate rather than uncharged osmolytes like taurine [PMID:28833202], and they transport cGAMP and 2'3'-cyclic dinucleotides across the plasma membrane, enabling cell-to-cell transfer of cGAMP and contributing to interferon-dependent anti-viral innate immunity, with Lrrc8e-deficient mice showing impaired responses to HSV-1 [PMID:32277911, PMID:33171122]. The voltage-dependent inactivation kinetics and anion selectivity of LRRC8A/E channels are governed by conserved charged residues in the first extracellular loop (EL1), and EL1 of LRRC8E is required for channel activity [PMID:27325695, PMID:29853476]. A defining feature of LRRC8A/E channels is their dramatic (>10-fold) activation by oxidation, opposite to the inhibition seen with LRRC8A/C and LRRC8A/D heteromers; this potentiation is mediated by oxidation of two intracellular cysteines, C424 and C448, which form a disulfide bond driving an activating conformational change [PMID:28841766, PMID:35861288]. In vivo, LRRC8E localizes specifically to renal collecting duct intercalated cells, distinct from other VRAC subunits, and its deletion does not produce the proximal tubulopathy caused by loss of LRRC8A or LRRC8D [PMID:35777784].","teleology":[{"year":2004,"claim":"Established LRRC8E as a member of the LRRC8 family with a predicted leucine-rich-repeat architecture, defining the candidate before any functional role was known.","evidence":"Bioinformatic sequence analysis and predicted structural comparison","pmids":["15094057"],"confidence":"Low","gaps":["Computational prediction only with no functional assay","Transmembrane topology and channel role unresolved at this stage"]},{"year":2015,"claim":"Placed LRRC8E within heteromeric VRACs and showed subunit-specific substrate handling, since LRRC8E-containing channels did not mediate cisplatin uptake unlike LRRC8A/D channels.","evidence":"Genetic knockout/knockdown of individual subunits with radiotracer and drug uptake assays","pmids":["26530471"],"confidence":"High","gaps":["Did not define which substrates LRRC8A/E channels do transport","Stoichiometry of LRRC8E in the hexamer not resolved"]},{"year":2016,"claim":"Mapped the structural determinants of LRRC8A/E gating and selectivity to conserved charged residues in EL1, explaining how LRRC8E shapes channel voltage-dependent inactivation and anion permeability.","evidence":"LRRC8C/LRRC8E chimeras, point mutagenesis and electrophysiology","pmids":["27325695"],"confidence":"High","gaps":["Atomic structure of the EL1 region not determined","Did not address physiological substrates"]},{"year":2016,"claim":"Demonstrated that LRRC8A/D/E expression alone is insufficient to reconstitute channel function, indicating additional required factors and constraining minimal-reconstitution models.","evidence":"siRNA knockdown and overexpression in KCP-4 and C127 cells with current measurements","pmids":["27764579"],"confidence":"Medium","gaps":["Identity of the additional required factor(s) unknown","Single lab and single method"]},{"year":2017,"claim":"Defined a functional specialization of LRRC8A/C/E channels in releasing charged organic osmolytes, distinguishing them from LRRC8A/D channels that release uncharged osmolytes.","evidence":"RNAi knockdown with radiotracer flux assays in primary rat astrocytes under hypoosmotic challenge","pmids":["28833202"],"confidence":"High","gaps":["Did not resolve the structural basis for charge selectivity","In vivo relevance in brain not tested"]},{"year":2017,"claim":"Revealed redox as a subunit-specific gating input, with LRRC8A/E channels potentiated >10-fold by oxidation while LRRC8A/C and LRRC8A/D are inhibited, establishing LRRC8E as a ROS-sensing VRAC subunit.","evidence":"Electrophysiology on tagged heteromers with oxidant treatment and comparison to Jurkat endogenous currents","pmids":["28841766"],"confidence":"High","gaps":["Molecular oxidation target not yet identified","Physiological oxidant source unclear"]},{"year":2018,"claim":"Showed EL1 of LRRC8E is essential for VRAC activity and that an LRRC8A intracellular sequence confers homomeric channel activity, dissecting the domains controlling assembly and permeation.","evidence":"Chimera and domain-swap experiments across LRRC8 subunits with electrophysiology","pmids":["29853476"],"confidence":"High","gaps":["No structural model of the functional chimeras","Endogenous assembly stoichiometry not addressed"]},{"year":2020,"claim":"Identified cGAMP and cyclic dinucleotides as physiological substrates of LRRC8A/E channels and linked the subunit to anti-viral innate immunity in vivo, where Lrrc8e-deficient mice showed impaired interferon responses and HSV-1 immunity.","evidence":"Biochemical transport assays, electrophysiology and Lrrc8e-knockout mice with HSV-1 infection and IFN readouts","pmids":["32277911"],"confidence":"High","gaps":["Directionality control across diverse cell contexts not fully mapped","Quantitative contribution relative to other transporters unresolved"]},{"year":2020,"claim":"Refined the cGAMP transport model by showing LRRC8A partners with LRRC8C and/or LRRC8E in an expression-dependent manner, with LRRC8D inhibitory, and that transport direction follows the electrochemical gradient.","evidence":"Genome-wide CRISPR screen with transport and electrophysiological assays in multiple human cell lines and primary cells","pmids":["33171122"],"confidence":"High","gaps":["Mechanism by which LRRC8D antagonizes cGAMP transport unknown","Regulation of subunit composition in vivo unclear"]},{"year":2021,"claim":"Uncovered a tonic activation mechanism whereby a serum protein and plasma-membrane-localized cGAS, via PIP2, open LRRC8A/E channels under isotonic conditions to support cGAMP transport.","evidence":"cGAS genetic analyses, serum proteinase K/heat treatment, transport assays and membrane fractionation","pmids":["33827893"],"confidence":"Medium","gaps":["PIP2 role lacks full reconstitution","Identity of the serum protein component not defined"]},{"year":2022,"claim":"Identified the molecular targets of redox activation as intracellular cysteines C424 and C448 in LRRC8E, whose disulfide formation drives the activating conformational change.","evidence":"Chimeric/concatemeric constructs, cysteine mutagenesis and electrophysiology with oxidants","pmids":["35861288"],"confidence":"High","gaps":["Disulfide bond not directly visualized structurally","Endogenous physiological oxidation conditions not established"]},{"year":2022,"claim":"Established a distinct in vivo localization and renal role, with LRRC8E confined to collecting duct intercalated cells and its deletion sparing proximal tubule function unlike LRRC8A/D loss.","evidence":"Epitope-tagged knock-in mice for localization and constitutive knockout with histology, urine/serum analysis and metabolomics","pmids":["35777784"],"confidence":"High","gaps":["Functional role within intercalated cells not defined","Substrate transported in this renal context unknown"]},{"year":2025,"claim":"Demonstrated that LRRC8E is dispensable for lymphocyte development and cGAMP-mediated anti-tumor immunity in vivo, narrowing the in vivo physiological contexts in which LRRC8E is non-redundant.","evidence":"Selective LRRC8 knockout mice with syngeneic tumor models, cytokine measurements and lymphocyte flow cytometry","pmids":["41419196"],"confidence":"Medium","gaps":["Negative result for a single context; other in vivo roles not excluded","Single lab","Compensating transporters not fully identified"]},{"year":null,"claim":"The physiological substrate and function of LRRC8E within renal intercalated cells, and the identity of the additional factors and serum components required for channel activation, remain unresolved.","evidence":"","pmids":[],"confidence":"Medium","gaps":["Endogenous role in intercalated cells uncharacterized","Required cofactor for reconstitution unidentified","Structural basis of redox gating not directly resolved"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0005215","term_label":"transporter activity","supporting_discovery_ids":[1,4,7,8]},{"term_id":"GO:0140299","term_label":"molecular sensor activity","supporting_discovery_ids":[5,10]},{"term_id":"GO:0140104","term_label":"molecular carrier activity","supporting_discovery_ids":[7,8]}],"localization":[{"term_id":"GO:0005886","term_label":"plasma membrane","supporting_discovery_ids":[7,9,11]}],"pathway":[{"term_id":"R-HSA-168256","term_label":"Immune System","supporting_discovery_ids":[7,8]},{"term_id":"R-HSA-382551","term_label":"Transport of small molecules","supporting_discovery_ids":[1,4,8]},{"term_id":"R-HSA-8953897","term_label":"Cellular responses to stimuli","supporting_discovery_ids":[5,10]}],"complexes":["LRRC8 volume-regulated anion channel (VRAC)"],"partners":["LRRC8A","LRRC8C","LRRC8D","CGAS"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"Q6NSJ5","full_name":"Volume-regulated anion channel subunit LRRC8E","aliases":["Leucine-rich repeat-containing protein 8E"],"length_aa":796,"mass_kda":90.2,"function":"Non-essential component of the volume-regulated anion channel (VRAC, also named VSOAC channel), an anion channel required to maintain a constant cell volume in response to extracellular or intracellular osmotic changes (PubMed:24790029, PubMed:26824658, PubMed:28193731). The VRAC channel conducts iodide better than chloride and can also conduct organic osmolytes like taurine (PubMed:24790029, PubMed:26824658). Mediates efflux of amino acids, such as aspartate, in response to osmotic stress (PubMed:28193731). The VRAC channel also mediates transport of immunoreactive cyclic dinucleotide GMP-AMP (2'-3'-cGAMP), an immune messenger produced in response to DNA virus in the cytosol (PubMed:33171122). Channel activity requires LRRC8A plus at least one other family member (LRRC8B, LRRC8C, LRRC8D or LRRC8E); channel characteristics depend on the precise subunit composition (PubMed:24790029, PubMed:26824658, PubMed:28193731). Also plays a role in lysosome homeostasis by forming functional lysosomal VRAC channels in response to low cytoplasmic ionic strength condition: lysosomal VRAC channels are necessary for the formation of large lysosome-derived vacuoles, which store and then expel excess water to maintain cytosolic water homeostasis (PubMed:33139539)","subcellular_location":"Cell membrane; Endoplasmic reticulum membrane; Lysosome membrane; Endoplasmic reticulum membrane","url":"https://www.uniprot.org/uniprotkb/Q6NSJ5/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/LRRC8E","classification":"Not Classified","n_dependent_lines":16,"n_total_lines":1208,"dependency_fraction":0.013245033112582781},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[{"gene":"CANX","stoichiometry":0.2},{"gene":"CCDC47","stoichiometry":0.2}],"url":"https://opencell.sf.czbiohub.org/search/LRRC8E","total_profiled":1310},"omim":[{"mim_id":"612891","title":"LEUCINE-RICH REPEAT-CONTAINING PROTEIN 8E; LRRC8E","url":"https://www.omim.org/entry/612891"},{"mim_id":"608360","title":"LEUCINE-RICH REPEAT-CONTAINING PROTEIN 8A; LRRC8A","url":"https://www.omim.org/entry/608360"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"","locations":[],"tissue_specificity":"Low tissue specificity","tissue_distribution":"Detected in many","driving_tissues":[],"url":"https://www.proteinatlas.org/search/LRRC8E"},"hgnc":{"alias_symbol":["FLJ23420"],"prev_symbol":[]},"alphafold":{"accession":"Q6NSJ5","domains":[{"cath_id":"1.20.1440","chopping":"17-58_95-142_254-362","consensus_level":"high","plddt":89.3396,"start":17,"end":362},{"cath_id":"3.80.10.10","chopping":"618-796","consensus_level":"medium","plddt":93.3278,"start":618,"end":796}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q6NSJ5","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q6NSJ5-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q6NSJ5-F1-predicted_aligned_error_v6.png","plddt_mean":84.06},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=LRRC8E","jax_strain_url":"https://www.jax.org/strain/search?query=LRRC8E"},"sequence":{"accession":"Q6NSJ5","fasta_url":"https://rest.uniprot.org/uniprotkb/Q6NSJ5.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q6NSJ5/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q6NSJ5"}},"corpus_meta":[{"pmid":"32277911","id":"PMC_32277911","title":"Transfer of cGAMP into Bystander Cells via LRRC8 Volume-Regulated Anion Channels Augments STING-Mediated Interferon Responses and Anti-viral Immunity.","date":"2020","source":"Immunity","url":"https://pubmed.ncbi.nlm.nih.gov/32277911","citation_count":244,"is_preprint":false},{"pmid":"26530471","id":"PMC_26530471","title":"Subunit composition of VRAC channels determines substrate specificity and cellular resistance to Pt-based anti-cancer drugs.","date":"2015","source":"The EMBO journal","url":"https://pubmed.ncbi.nlm.nih.gov/26530471","citation_count":225,"is_preprint":false},{"pmid":"33171122","id":"PMC_33171122","title":"LRRC8A:C/E Heteromeric Channels Are Ubiquitous Transporters of cGAMP.","date":"2020","source":"Molecular cell","url":"https://pubmed.ncbi.nlm.nih.gov/33171122","citation_count":155,"is_preprint":false},{"pmid":"28833202","id":"PMC_28833202","title":"Molecular composition and heterogeneity of the LRRC8-containing swelling-activated osmolyte channels in primary rat astrocytes.","date":"2017","source":"The Journal of physiology","url":"https://pubmed.ncbi.nlm.nih.gov/28833202","citation_count":85,"is_preprint":false},{"pmid":"27325695","id":"PMC_27325695","title":"Inactivation and Anion Selectivity of Volume-regulated Anion Channels (VRACs) Depend on C-terminal Residues of the First Extracellular Loop.","date":"2016","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/27325695","citation_count":50,"is_preprint":false},{"pmid":"28841766","id":"PMC_28841766","title":"Subunit-dependent oxidative stress sensitivity of LRRC8 volume-regulated anion channels.","date":"2017","source":"The Journal of physiology","url":"https://pubmed.ncbi.nlm.nih.gov/28841766","citation_count":48,"is_preprint":false},{"pmid":"15094057","id":"PMC_15094057","title":"LRRC8 involved in B cell development belongs to a novel family of leucine-rich repeat proteins.","date":"2004","source":"FEBS letters","url":"https://pubmed.ncbi.nlm.nih.gov/15094057","citation_count":47,"is_preprint":false},{"pmid":"31691355","id":"PMC_31691355","title":"LINC00958 facilitates cervical cancer cell proliferation and metastasis by sponging miR-625-5p to upregulate LRRC8E expression.","date":"2019","source":"Journal of cellular biochemistry","url":"https://pubmed.ncbi.nlm.nih.gov/31691355","citation_count":44,"is_preprint":false},{"pmid":"29853476","id":"PMC_29853476","title":"Intracellular and extracellular loops of LRRC8 are essential for volume-regulated anion channel function.","date":"2018","source":"The Journal of general physiology","url":"https://pubmed.ncbi.nlm.nih.gov/29853476","citation_count":39,"is_preprint":false},{"pmid":"27764579","id":"PMC_27764579","title":"Specific and essential but not sufficient roles of LRRC8A in the activity of volume-sensitive outwardly rectifying anion channel (VSOR).","date":"2016","source":"Channels (Austin, Tex.)","url":"https://pubmed.ncbi.nlm.nih.gov/27764579","citation_count":33,"is_preprint":false},{"pmid":"28972132","id":"PMC_28972132","title":"Leucine-rich repeat-containing 8B protein is associated with the endoplasmic reticulum Ca2+ leak in HEK293 cells.","date":"2017","source":"Journal of cell science","url":"https://pubmed.ncbi.nlm.nih.gov/28972132","citation_count":25,"is_preprint":false},{"pmid":"35777784","id":"PMC_35777784","title":"Renal Deletion of LRRC8/VRAC Channels Induces Proximal Tubulopathy.","date":"2022","source":"Journal of the American Society of Nephrology : JASN","url":"https://pubmed.ncbi.nlm.nih.gov/35777784","citation_count":20,"is_preprint":false},{"pmid":"33827893","id":"PMC_33827893","title":"Regulation of Anion Channel LRRC8 Volume-Regulated Anion Channels in Transport of 2'3'-Cyclic GMP-AMP and Cisplatin under Steady State and Inflammation.","date":"2021","source":"Journal of immunology (Baltimore, Md. : 1950)","url":"https://pubmed.ncbi.nlm.nih.gov/33827893","citation_count":20,"is_preprint":false},{"pmid":"35861288","id":"PMC_35861288","title":"Molecular determinants underlying volume-regulated anion channel subunit-dependent oxidation sensitivity.","date":"2022","source":"The Journal of physiology","url":"https://pubmed.ncbi.nlm.nih.gov/35861288","citation_count":18,"is_preprint":false},{"pmid":"25552532","id":"PMC_25552532","title":"A simple method for estimating the strength of natural selection on overlapping genes.","date":"2014","source":"Genome biology and evolution","url":"https://pubmed.ncbi.nlm.nih.gov/25552532","citation_count":16,"is_preprint":false},{"pmid":"34620745","id":"PMC_34620745","title":"LncRNA PCAT6 activated by SP1 facilitates the progression of breast cancer by the miR-326/LRRC8E axis.","date":"2022","source":"Anti-cancer drugs","url":"https://pubmed.ncbi.nlm.nih.gov/34620745","citation_count":8,"is_preprint":false},{"pmid":"27610895","id":"PMC_27610895","title":"Association between genes on chromosome 19p13.2 and panic disorder.","date":"2016","source":"Psychiatric genetics","url":"https://pubmed.ncbi.nlm.nih.gov/27610895","citation_count":7,"is_preprint":false},{"pmid":"35363093","id":"PMC_35363093","title":"Knockdown of LINC00511 decreased cisplatin resistance in non-small cell lung cancer by elevating miR-625 level to suppress the expression of leucine rich repeat containing eight volume-regulated anion channel subunit E.","date":"2022","source":"Human & experimental toxicology","url":"https://pubmed.ncbi.nlm.nih.gov/35363093","citation_count":7,"is_preprint":false},{"pmid":"39449805","id":"PMC_39449805","title":"Unveiling the therapeutic potential: KBU2046 halts triple-negative breast cancer cell migration by constricting TGF-β1 activation in vitro.","date":"2024","source":"Oncology research","url":"https://pubmed.ncbi.nlm.nih.gov/39449805","citation_count":3,"is_preprint":false},{"pmid":"41419196","id":"PMC_41419196","title":"A protective cGAMP-mediated anti-tumor immune response can proceed without LRRC8/VRAC channels.","date":"2025","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/41419196","citation_count":0,"is_preprint":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":12845,"output_tokens":3644,"usd":0.046598,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":11110,"output_tokens":3916,"usd":0.076725,"stage2_stop_reason":"end_turn"},"total_usd":0.123323,"stage1_batch_id":"msgbatch_01BbTCMyrRPyhtEq6b1MdwCN","stage2_batch_id":"msgbatch_011dEed5bbxYvTAaQWKJevxu","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2004,\n      \"finding\": \"LRRC8E (FLJ23420) was identified as a member of the LRRC8 family, predicted to encode a protein with 16 extracellular leucine-rich repeats but lacking four transmembrane regions present in the other family members, suggesting a distinct structural configuration.\",\n      \"method\": \"Bioinformatic sequence analysis and predicted structural comparison\",\n      \"journal\": \"FEBS letters\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 4 / Weak — computational/bioinformatic prediction only, no functional assay performed\",\n      \"pmids\": [\"15094057\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"LRRC8E is a subunit of heteromeric LRRC8 volume-regulated anion channels (VRACs); however, LRRC8E-containing (but not LRRC8D-containing) VRACs do not contribute significantly to cisplatin uptake under isotonic conditions, whereas LRRC8A/LRRC8D channels are the primary mediators of cisplatin transport.\",\n      \"method\": \"Genetic knockout/knockdown of individual LRRC8 subunits combined with radiotracer and drug uptake assays\",\n      \"journal\": \"The EMBO journal\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — genetic ablation with functional readout, replicated across subunits with clear subunit-specificity, published in peer-reviewed journal\",\n      \"pmids\": [\"26530471\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"The C-terminal part of the first extracellular loop (EL1) of LRRC8E, specifically two conserved charged residues equivalent to Lys-98 and Asp-100 in LRRC8A, determines voltage-dependent inactivation kinetics and contributes to iodide/chloride selectivity of LRRC8A/E heteromeric VRACs.\",\n      \"method\": \"Chimera construction between LRRC8C and LRRC8E, point mutagenesis, electrophysiology\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — in vitro mutagenesis combined with electrophysiological functional validation, multiple mutations tested in a single rigorous study\",\n      \"pmids\": [\"27325695\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"Overexpression of LRRC8A alone or together with LRRC8D or LRRC8E in VSOR-deficient KCP-4 cells failed to restore VSOR activity, indicating that LRRC8A/D/E expression alone is not sufficient for channel function and that additional unidentified factors are required.\",\n      \"method\": \"siRNA knockdown and overexpression in KCP-4 and C127 cells with electrophysiological current measurements\",\n      \"journal\": \"Channels (Austin, Tex.)\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Weak — clean KO/OE with defined electrophysiological readout, but single lab and single method\",\n      \"pmids\": [\"27764579\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"In primary rat astrocytes, LRRC8A/C/E-containing heteromeric VRACs preferentially mediate swelling-activated release of charged organic osmolytes (d-aspartate), while LRRC8A/D channels dominate release of uncharged osmolytes (taurine, myo-inositol). Knockdown of LRRC8C+LRRC8E selectively reduced d-aspartate efflux without major effect on taurine release.\",\n      \"method\": \"RNAi knockdown of individual LRRC8 subunits combined with radiotracer flux assays in primary rat astrocytes under hypoosmotic challenge\",\n      \"journal\": \"The Journal of physiology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — RNAi with radiotracer functional assay, multiple subunit combinations tested, orthogonal osmolytes used as readouts\",\n      \"pmids\": [\"28833202\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"LRRC8A/LRRC8E heteromeric channels are dramatically activated (>10-fold potentiation) by oxidation of intracellular cysteine residues via chloramine-T or tert-butyl hydroperoxide, in contrast to LRRC8A/LRRC8C and LRRC8A/LRRC8D heteromers which are inhibited by oxidation, demonstrating direct subunit-dependent modulation of VRAC by reactive oxygen species.\",\n      \"method\": \"Electrophysiology on fluorescently-tagged LRRC8 heteromers expressed in cells, oxidant treatment, comparison with Jurkat T lymphocyte endogenous currents\",\n      \"journal\": \"The Journal of physiology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — electrophysiological functional assay with multiple oxidants, subunit-specific comparison, corroborated with endogenous currents in Jurkat cells\",\n      \"pmids\": [\"28841766\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"The first extracellular loop (EL1) connecting transmembrane domains 1 and 2 of LRRC8E is essential for VRAC activity. Replacing EL1 of LRRC8A with that of LRRC8E in a chimeric construct generates homomeric VRACs with normal volume-dependent regulation. A 25-amino acid sequence unique to the LRRC8A intracellular loop, when inserted into LRRC8E, is sufficient to generate homomeric VRAC activity, and influences anion permeability, rectification, and voltage sensitivity.\",\n      \"method\": \"Chimera construction and domain-swap experiments between LRRC8A, LRRC8C, LRRC8D, and LRRC8E; electrophysiology\",\n      \"journal\": \"The Journal of general physiology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — structure-function chimera analysis with electrophysiological validation, multiple chimeras and subunits tested in a single rigorous study\",\n      \"pmids\": [\"29853476\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"LRRC8A/LRRC8E-containing VRACs transport cGAMP and cyclic dinucleotides across the plasma membrane, mediating cell-to-cell transfer of cGAMP. Lrrc8e−/− mice exhibited impaired interferon responses and compromised immunity to HSV-1, establishing LRRC8E as a functionally important subunit for cGAMP transport and anti-viral innate immunity.\",\n      \"method\": \"Biochemical transport assays, electrophysiology, genetic knockout mice (Lrrc8e−/−), viral infection assays (HSV-1), IFN response measurement\",\n      \"journal\": \"Immunity\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — multiple orthogonal methods (biochemical, electrophysiological, in vivo genetic), replicated across cell types and validated with in vivo mouse model\",\n      \"pmids\": [\"32277911\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"LRRC8A forms complexes with LRRC8C and/or LRRC8E depending on their expression levels to transport cGAMP and other 2'3'-cyclic dinucleotides; in contrast, LRRC8D inhibits cGAMP transport. cGAMP is effluxed or influxed via LRRC8 channels depending on the electrochemical gradient. LRRC8A/C/E channels are key cGAMP transporters in resting primary human vasculature cells and universal human cGAMP transporters when activated.\",\n      \"method\": \"Genome-wide CRISPR screen, genetic knockout/overexpression, transport assays, electrophysiology in multiple human cell lines and primary cells\",\n      \"journal\": \"Molecular cell\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — CRISPR screen plus orthogonal transport and electrophysiological assays, multiple cell types including primary human cells, independently published from different lab than PMID:32277911\",\n      \"pmids\": [\"33171122\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"LRRC8A/E-containing VRACs specialized in cGAMP transport can be opened by a protein component in serum under resting (isotonic) conditions; serum depletion ablates tonic LRRC8A/E VRAC activity and decreases cGAMP transport. The plasma membrane-localized form of cGAS (not its DNA-binding or enzymatic activity) enables VRAC activation, and phospholipid PIP2 is instrumental in membrane localization of cGAS and its association with VRACs.\",\n      \"method\": \"Genetic analyses (cGAS knockouts/mutants), proteinase K and heat treatment of serum, cGAMP transport assays, membrane fractionation\",\n      \"journal\": \"Journal of immunology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — multiple genetic and biochemical approaches in a single lab, but some mechanistic claims (PIP2 role) lack full reconstitution\",\n      \"pmids\": [\"33827893\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"Two intracellular cysteines in the first two leucine-rich repeats of LRRC8E (C424 and C448) are the molecular targets of oxidation. Oxidation likely forms a disulfide bond between these two cysteines, inducing a conformational change that activates LRRC8A/LRRC8E heteromeric channels.\",\n      \"method\": \"Chimeric and concatemeric LRRC8 constructs, site-directed mutagenesis of specific cysteines, electrophysiology with oxidant treatment\",\n      \"journal\": \"The Journal of physiology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — mutagenesis of specific residues combined with electrophysiological functional readout, concatemeric strategy to control subunit stoichiometry, multiple oxidants tested\",\n      \"pmids\": [\"35861288\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"In the kidney, LRRC8E localizes specifically to intercalated cells of the collecting duct, a distinct localization from other VRAC subunits (LRRC8A, LRRC8B, LRRC8D in basolateral membranes of proximal tubules; LRRC8C exclusively in vascular endothelium). Constitutive deletion of Lrrc8e did not cause proximal tubulopathy (unlike Lrrc8d or Lrrc8a deletion), suggesting LRRC8E plays a distinct renal role.\",\n      \"method\": \"Epitope-tagged knock-in mice for localization, constitutive knockout mice with histology and urine/serum functional analysis, metabolomics\",\n      \"journal\": \"Journal of the American Society of Nephrology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — direct localization by epitope tagging in vivo combined with genetic knockout phenotypic analysis, multiple subunits compared in parallel\",\n      \"pmids\": [\"35777784\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"Disruption of LRRC8E (along with LRRC8B, LRRC8C, or LRRC8D) had no discernible effect on T or B cell development in mice. In subcutaneous tumor models, disruption of LRRC8E in host cells did not impair the cGAMP-mediated anti-tumor immune response, indicating that VRAC-mediated cGAMP transport involving LRRC8E is dispensable for anti-tumor immunity in vivo, which is instead primarily mediated by other transporters.\",\n      \"method\": \"Genetic knockout mice with selective LRRC8 subunit disruptions, syngeneic subcutaneous tumor models (MC38, B16-F10), serum cytokine measurements, tumor growth assays, flow cytometry of lymphocyte development\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Weak — clean in vivo genetic knockout with defined phenotypic readout, but single lab and the finding is a negative result for LRRC8E-specific contribution in this context\",\n      \"pmids\": [\"41419196\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"LRRC8E is a non-essential accessory subunit of heteromeric LRRC8 volume-regulated anion channels (VRACs), forming hexameric complexes with the obligatory LRRC8A subunit; LRRC8A/LRRC8E channels preferentially transport charged substrates including cGAMP and cyclic dinucleotides (mediating innate immune signaling), are uniquely activated (>10-fold) by oxidation of two intracellular cysteines (C424 and C448) via disulfide bond formation, and exhibit distinct voltage-dependent inactivation and anion selectivity determined by conserved charged residues in the first extracellular loop; in vivo, LRRC8E localizes specifically to renal intercalated cells and its deletion does not cause the proximal tubulopathy seen with LRRC8A/D loss, while its role in cGAMP-mediated anti-tumor immunity in vivo appears dispensable.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"LRRC8E is an accessory subunit of heteromeric LRRC8 volume-regulated anion channels (VRACs), assembling with the obligatory LRRC8A subunit to form channels with subunit-specific transport and gating properties [#1, #4]. LRRC8A/E channels confer distinct functional signatures: they preferentially mediate swelling-activated efflux of charged organic osmolytes such as d-aspartate rather than uncharged osmolytes like taurine [#4], and they transport cGAMP and 2'3'-cyclic dinucleotides across the plasma membrane, enabling cell-to-cell transfer of cGAMP and contributing to interferon-dependent anti-viral innate immunity, with Lrrc8e-deficient mice showing impaired responses to HSV-1 [#7, #8]. The voltage-dependent inactivation kinetics and anion selectivity of LRRC8A/E channels are governed by conserved charged residues in the first extracellular loop (EL1), and EL1 of LRRC8E is required for channel activity [#2, #6]. A defining feature of LRRC8A/E channels is their dramatic (>10-fold) activation by oxidation, opposite to the inhibition seen with LRRC8A/C and LRRC8A/D heteromers; this potentiation is mediated by oxidation of two intracellular cysteines, C424 and C448, which form a disulfide bond driving an activating conformational change [#5, #10]. In vivo, LRRC8E localizes specifically to renal collecting duct intercalated cells, distinct from other VRAC subunits, and its deletion does not produce the proximal tubulopathy caused by loss of LRRC8A or LRRC8D [#11].\",\n  \"teleology\": [\n    {\n      \"year\": 2004,\n      \"claim\": \"Established LRRC8E as a member of the LRRC8 family with a predicted leucine-rich-repeat architecture, defining the candidate before any functional role was known.\",\n      \"evidence\": \"Bioinformatic sequence analysis and predicted structural comparison\",\n      \"pmids\": [\"15094057\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"Computational prediction only with no functional assay\", \"Transmembrane topology and channel role unresolved at this stage\"]\n    },\n    {\n      \"year\": 2015,\n      \"claim\": \"Placed LRRC8E within heteromeric VRACs and showed subunit-specific substrate handling, since LRRC8E-containing channels did not mediate cisplatin uptake unlike LRRC8A/D channels.\",\n      \"evidence\": \"Genetic knockout/knockdown of individual subunits with radiotracer and drug uptake assays\",\n      \"pmids\": [\"26530471\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not define which substrates LRRC8A/E channels do transport\", \"Stoichiometry of LRRC8E in the hexamer not resolved\"]\n    },\n    {\n      \"year\": 2016,\n      \"claim\": \"Mapped the structural determinants of LRRC8A/E gating and selectivity to conserved charged residues in EL1, explaining how LRRC8E shapes channel voltage-dependent inactivation and anion permeability.\",\n      \"evidence\": \"LRRC8C/LRRC8E chimeras, point mutagenesis and electrophysiology\",\n      \"pmids\": [\"27325695\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Atomic structure of the EL1 region not determined\", \"Did not address physiological substrates\"]\n    },\n    {\n      \"year\": 2016,\n      \"claim\": \"Demonstrated that LRRC8A/D/E expression alone is insufficient to reconstitute channel function, indicating additional required factors and constraining minimal-reconstitution models.\",\n      \"evidence\": \"siRNA knockdown and overexpression in KCP-4 and C127 cells with current measurements\",\n      \"pmids\": [\"27764579\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Identity of the additional required factor(s) unknown\", \"Single lab and single method\"]\n    },\n    {\n      \"year\": 2017,\n      \"claim\": \"Defined a functional specialization of LRRC8A/C/E channels in releasing charged organic osmolytes, distinguishing them from LRRC8A/D channels that release uncharged osmolytes.\",\n      \"evidence\": \"RNAi knockdown with radiotracer flux assays in primary rat astrocytes under hypoosmotic challenge\",\n      \"pmids\": [\"28833202\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not resolve the structural basis for charge selectivity\", \"In vivo relevance in brain not tested\"]\n    },\n    {\n      \"year\": 2017,\n      \"claim\": \"Revealed redox as a subunit-specific gating input, with LRRC8A/E channels potentiated >10-fold by oxidation while LRRC8A/C and LRRC8A/D are inhibited, establishing LRRC8E as a ROS-sensing VRAC subunit.\",\n      \"evidence\": \"Electrophysiology on tagged heteromers with oxidant treatment and comparison to Jurkat endogenous currents\",\n      \"pmids\": [\"28841766\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Molecular oxidation target not yet identified\", \"Physiological oxidant source unclear\"]\n    },\n    {\n      \"year\": 2018,\n      \"claim\": \"Showed EL1 of LRRC8E is essential for VRAC activity and that an LRRC8A intracellular sequence confers homomeric channel activity, dissecting the domains controlling assembly and permeation.\",\n      \"evidence\": \"Chimera and domain-swap experiments across LRRC8 subunits with electrophysiology\",\n      \"pmids\": [\"29853476\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"No structural model of the functional chimeras\", \"Endogenous assembly stoichiometry not addressed\"]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"Identified cGAMP and cyclic dinucleotides as physiological substrates of LRRC8A/E channels and linked the subunit to anti-viral innate immunity in vivo, where Lrrc8e-deficient mice showed impaired interferon responses and HSV-1 immunity.\",\n      \"evidence\": \"Biochemical transport assays, electrophysiology and Lrrc8e-knockout mice with HSV-1 infection and IFN readouts\",\n      \"pmids\": [\"32277911\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Directionality control across diverse cell contexts not fully mapped\", \"Quantitative contribution relative to other transporters unresolved\"]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"Refined the cGAMP transport model by showing LRRC8A partners with LRRC8C and/or LRRC8E in an expression-dependent manner, with LRRC8D inhibitory, and that transport direction follows the electrochemical gradient.\",\n      \"evidence\": \"Genome-wide CRISPR screen with transport and electrophysiological assays in multiple human cell lines and primary cells\",\n      \"pmids\": [\"33171122\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Mechanism by which LRRC8D antagonizes cGAMP transport unknown\", \"Regulation of subunit composition in vivo unclear\"]\n    },\n    {\n      \"year\": 2021,\n      \"claim\": \"Uncovered a tonic activation mechanism whereby a serum protein and plasma-membrane-localized cGAS, via PIP2, open LRRC8A/E channels under isotonic conditions to support cGAMP transport.\",\n      \"evidence\": \"cGAS genetic analyses, serum proteinase K/heat treatment, transport assays and membrane fractionation\",\n      \"pmids\": [\"33827893\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"PIP2 role lacks full reconstitution\", \"Identity of the serum protein component not defined\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Identified the molecular targets of redox activation as intracellular cysteines C424 and C448 in LRRC8E, whose disulfide formation drives the activating conformational change.\",\n      \"evidence\": \"Chimeric/concatemeric constructs, cysteine mutagenesis and electrophysiology with oxidants\",\n      \"pmids\": [\"35861288\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Disulfide bond not directly visualized structurally\", \"Endogenous physiological oxidation conditions not established\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Established a distinct in vivo localization and renal role, with LRRC8E confined to collecting duct intercalated cells and its deletion sparing proximal tubule function unlike LRRC8A/D loss.\",\n      \"evidence\": \"Epitope-tagged knock-in mice for localization and constitutive knockout with histology, urine/serum analysis and metabolomics\",\n      \"pmids\": [\"35777784\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Functional role within intercalated cells not defined\", \"Substrate transported in this renal context unknown\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Demonstrated that LRRC8E is dispensable for lymphocyte development and cGAMP-mediated anti-tumor immunity in vivo, narrowing the in vivo physiological contexts in which LRRC8E is non-redundant.\",\n      \"evidence\": \"Selective LRRC8 knockout mice with syngeneic tumor models, cytokine measurements and lymphocyte flow cytometry\",\n      \"pmids\": [\"41419196\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Negative result for a single context; other in vivo roles not excluded\", \"Single lab\", \"Compensating transporters not fully identified\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"The physiological substrate and function of LRRC8E within renal intercalated cells, and the identity of the additional factors and serum components required for channel activation, remain unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Endogenous role in intercalated cells uncharacterized\", \"Required cofactor for reconstitution unidentified\", \"Structural basis of redox gating not directly resolved\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0005215\", \"supporting_discovery_ids\": [1, 4, 7, 8]},\n      {\"term_id\": \"GO:0140299\", \"supporting_discovery_ids\": [5, 10]},\n      {\"term_id\": \"GO:0140104\", \"supporting_discovery_ids\": [7, 8]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005886\", \"supporting_discovery_ids\": [7, 9, 11]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-168256\", \"supporting_discovery_ids\": [7, 8]},\n      {\"term_id\": \"R-HSA-382551\", \"supporting_discovery_ids\": [1, 4, 8]},\n      {\"term_id\": \"R-HSA-8953897\", \"supporting_discovery_ids\": [5, 10]}\n    ],\n    \"complexes\": [\"LRRC8 volume-regulated anion channel (VRAC)\"],\n    \"partners\": [\"LRRC8A\", \"LRRC8C\", \"LRRC8D\", \"CGAS\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":5,"faith_total":5,"faith_pct":100.0}}