{"gene":"LRRC8B","run_date":"2026-06-10T02:59:50","timeline":{"discoveries":[{"year":2004,"finding":"LRRC8B (TA-LRRP) was identified as a member of a novel family of leucine-rich repeat proteins. The predicted structure includes 16 extracellular leucine-rich repeats and four transmembrane regions, similar to LRRC8A and other family members.","method":"Sequence analysis and structural prediction of novel LRRC8-like genes","journal":"FEBS letters","confidence":"Low","confidence_rationale":"Tier 4 / Weak — computational/bioinformatic prediction only, no functional experiments on LRRC8B specifically","pmids":["15094057"],"is_preprint":false},{"year":2014,"finding":"LRRC8D interacts with LRRC8A, LRRC8B, and LRRC8C, as demonstrated by co-immunoprecipitation. LRRC8 proteins including LRRC8B localize to the plasma membrane with defined topology, supporting roles in solute transport.","method":"Co-immunoprecipitation, localization and topology experiments","journal":"The Journal of biological chemistry","confidence":"Medium","confidence_rationale":"Tier 3 / Moderate — direct co-IP establishing LRRC8B as an interaction partner of LRRC8D, with localization data, single lab","pmids":["24782309"],"is_preprint":false},{"year":2014,"finding":"LRRC8A is an indispensable component of the volume-regulated anion channel (VRAC), which is a heteromeric complex requiring LRRC8A plus at least one of LRRC8B-E subunits to mediate swelling-activated Cl- currents and organic osmolyte release.","method":"siRNA knockdown, radiotracer assays, quantitative RT-PCR in primary rat astrocytes","journal":"The Journal of physiology","confidence":"High","confidence_rationale":"Tier 2 / Strong — reciprocal functional knockdown with multiple substrate readouts, independently replicated across multiple labs","pmids":["25172945"],"is_preprint":false},{"year":2017,"finding":"LRRC8B is a component of heteromeric VRAC complexes in astrocytes. Knockdown of LRRC8B alone did not significantly alter swelling-activated release of charged (d-aspartate) or uncharged (taurine, myo-inositol) osmolytes, but combined silencing of LRRC8C+LRRC8D strongly inhibited all osmolyte release, placing LRRC8B as a complementary but non-dominant subunit.","method":"RNAi knockdown, radiotracer assays in primary rat astrocytes","journal":"The Journal of physiology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — clean RNAi with multiple substrate readouts, single lab, LRRC8B-specific effect was largely negative (non-dominant role)","pmids":["28833202"],"is_preprint":false},{"year":2017,"finding":"LRRC8B overexpression in HEK293 cells reduced ER Ca2+ levels and increased ER Ca2+ leak. LRRC8B-overexpressing cells showed reduced IP3-stimulated Ca2+ release and enhanced store-operated Ca2+ entry, while LRRC8B-knockdown cells showed slower TG-induced ER Ca2+ depletion. These data establish LRRC8B as a Ca2+ leak channel in the ER membrane.","method":"Overexpression and siRNA knockdown in HEK293 cells, intracellular Ca2+ measurements, thapsigargin block experiments, IP3 stimulation assays","journal":"Journal of cell science","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — both gain-of-function and loss-of-function approaches with multiple readouts, single lab","pmids":["28972132"],"is_preprint":false},{"year":2017,"finding":"LRRC8A-LRRC8E heteromeric channels are activated by oxidation of intracellular cysteines, whereas LRRC8A-LRRC8C and LRRC8A-LRRC8D heteromers are inhibited by oxidation. The subunit-dependent oxidation sensitivity shows LRRC8 channel proteins are directly modulated by ROS. LRRC8B-containing heteromers were not specifically tested for oxidation sensitivity in this study.","method":"Electrophysiology of fluorescently tagged LRRC8 heteromers expressed in cells, treatment with chloramine-T and tert-butyl hydroperoxide","journal":"The Journal of physiology","confidence":"Medium","confidence_rationale":"Tier 1 / Moderate — direct electrophysiology with chemical probes, single lab; LRRC8B specifically not characterized for oxidation","pmids":["28841766"],"is_preprint":false},{"year":2019,"finding":"Immunoprecipitation of LRRC8A co-precipitates LRRC8B (along with LRRC8C, D, E), confirming LRRC8B is a bona fide partner in endogenous VRAC heterohexameric complexes. Quantitative immunoblotting revealed tissue-specific expression patterns of LRRC8B with generally low absolute amounts.","method":"Quantitative immunoblotting using recombinant protein calibration, immunoprecipitation of endogenous LRRC8A from mouse cell lines and tissues","journal":"International journal of molecular sciences","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — co-IP from endogenous proteins with quantitative calibration, single lab","pmids":["31771171"],"is_preprint":false},{"year":2022,"finding":"LRRC8A and LRRC8B (along with LRRC8D) are expressed in basolateral membranes of proximal tubules in the kidney. Constitutive deletion of LRRC8D and conditional deletion of LRRC8A in proximal tubules cause proximal tubular injury and mild Fanconi-like symptoms, establishing that LRRC8A/D-containing VRACs are required for basolateral exit of organic compounds in proximal tubules. LRRC8B co-localizes with LRRC8A at basolateral membranes.","method":"Epitope-tagged knock-in mice, immunohistochemistry, constitutive and conditional knockout mouse models, urine/serum analysis, metabolomics","journal":"Journal of the American Society of Nephrology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — genetic models with functional readouts in vivo, but LRRC8B-specific functional contribution not directly demonstrated (co-localization established, not specific knockout)","pmids":["35777784"],"is_preprint":false},{"year":2023,"finding":"Cryo-EM structures of heterohexameric LRRC8A:C channels revealed the structural basis for heteromeric VRAC assembly, including heterotypic LRR domain interactions that displace subunits and lipid gating in the pore. While this study focused on LRRC8A:C, the findings establish general principles of how complementary LRRC8 subunits (including LRRC8B) determine channel architecture through LRR domain interactions.","method":"Single-particle cryo-EM with fiducial-tagging strategy, electrophysiology","journal":"Nature structural & molecular biology","confidence":"High","confidence_rationale":"Tier 1 / Strong — high-resolution cryo-EM structures with functional validation by electrophysiology, reveals general mechanism for heteromeric subunit assembly relevant to LRRC8B","pmids":["36928458"],"is_preprint":false},{"year":2025,"finding":"In endothelial cells, co-immunoprecipitation from Lrrc8a-3xFlag knock-in mice and Lrrc8c-HA knock-in mice revealed enrichment of LRRC8A/B/C heteromers as the predominant endothelial LRRC8 complex. Lrrc8a/b/c depletion showed co-dependent expression of LRRC8A, LRRC8B, and LRRC8C (but not LRRC8D), establishing LRRC8B as a structural component of the endothelial VRAC complex.","method":"Co-immunoprecipitation from knock-in mice, endothelium-specific knockout/knockdown, electrophysiology, pressure myography","journal":"bioRxiv (preprint)","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — reciprocal co-IP from knock-in mice with functional readouts; preprint, not yet peer-reviewed","pmids":["40894750"],"is_preprint":true},{"year":2026,"finding":"Co-immunoprecipitation from endothelium-specific Lrrc8a-3xFlag overexpression mice confirmed LRRC8A/B/C form the endothelial LRRC8 heteromeric complex. LRRC8B shows co-dependent expression with LRRC8A and LRRC8C in endothelium (but not LRRC8D). LRRC8B is part of the mechanoresponsive endothelial VRAC that regulates AKT-eNOS signaling and vascular tone.","method":"Co-immunoprecipitation from epitope-tagged knock-in mice, endothelium-specific knockout, electrophysiology, pressure myography, angiotensin-induced hypertension model","journal":"Hypertension","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — reciprocal co-IP with in vivo functional readouts, single lab, LRRC8B-specific functional role not independently demonstrated from LRRC8A/C","pmids":["41636028"],"is_preprint":false},{"year":2025,"finding":"LRRC8B silencing alone did not reduce swelling-activated glutamate-analogue (D-[3H]aspartate) release from astrocytes, but LRRC8B knockdown partially rescued glutamate release in LRRC8C- or LRRC8D-knockdown cells, suggesting LRRC8B has a possible structural role in astrocytic VRACs without being a primary determinant of glutamate permeability.","method":"RNAi knockdown in primary mouse astrocytes, radiotracer release assays, qPCR, RNA-seq","journal":"bioRxiv (preprint)","confidence":"Low","confidence_rationale":"Tier 3 / Weak — single lab, preprint, LRRC8B-specific role inferred from partial rescue in double-knockdown conditions","pmids":["40766626"],"is_preprint":true},{"year":2025,"finding":"Disruption of LRRC8B in mice had no discernible effect on T or B cell development, establishing that LRRC8B is not required for lymphocyte development in vivo.","method":"Constitutive LRRC8B knockout mice analyzed for T and B cell development","journal":"The Journal of biological chemistry","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — in vivo genetic loss-of-function with defined immunological readout; negative result","pmids":["41419196"],"is_preprint":false}],"current_model":"LRRC8B is a complementary (non-essential) subunit of the heterohexameric volume-regulated anion channel (VRAC), assembling with the obligate LRRC8A subunit and other LRRC8 paralogs; in endothelial cells it forms a predominant LRRC8A/B/C complex that supports AKT-eNOS signaling and vascular tone, while in astrocytes its silencing alone does not substantially alter swelling-activated organic osmolyte release; additionally, overexpression studies indicate LRRC8B can function as an ER Ca2+ leak channel, and LRRC8B knockout mice show no defect in lymphocyte development."},"narrative":{"mechanistic_narrative":"LRRC8B is a complementary, non-obligate subunit of the heterohexameric volume-regulated anion channel (VRAC), assembling with the indispensable LRRC8A subunit and other LRRC8 paralogs (C, D, E) into endogenous channel complexes [PMID:25172945, PMID:31771171]. Co-immunoprecipitation of endogenous LRRC8A consistently recovers LRRC8B as a bona fide partner, and cryo-EM of LRRC8A:C heterohexamers defines how complementary subunits assemble through heterotypic leucine-rich-repeat domain interactions and lipid-dependent pore gating [PMID:31771171, PMID:36928458]. LRRC8B occupies a structural but non-dominant role: silencing LRRC8B alone does not appreciably alter swelling-activated release of charged or uncharged osmolytes from astrocytes, in contrast to the strong suppression seen with combined LRRC8C/D loss [PMID:28833202]. In endothelial cells, LRRC8B is part of a predominant LRRC8A/B/C complex whose subunits are co-dependent for expression, and this mechanoresponsive VRAC regulates AKT-eNOS signaling and vascular tone [PMID:41636028]. Beyond its role within VRAC, overexpression and knockdown studies place LRRC8B in the ER membrane as a Ca2+ leak channel, where it lowers ER Ca2+ stores and shapes store-operated Ca2+ entry [PMID:28972132]. Constitutive LRRC8B knockout mice show no defect in T or B cell development, indicating it is dispensable for lymphocyte development in vivo [PMID:41419196].","teleology":[{"year":2004,"claim":"Before any functional data, the question was whether LRRC8B belonged to a coherent protein family with a shared architecture; sequence analysis established it as a member of the LRRC8 family with extracellular leucine-rich repeats and four transmembrane regions.","evidence":"Sequence analysis and structural prediction of novel LRRC8-like genes","pmids":["15094057"],"confidence":"Low","gaps":["Computational prediction only","No functional assay on LRRC8B","Topology and membrane targeting not experimentally verified"]},{"year":2014,"claim":"The open question of whether LRRC8B physically associates with other family members was answered by showing it co-immunoprecipitates with LRRC8D and localizes to the plasma membrane with a defined topology, establishing it as a candidate transport-complex subunit.","evidence":"Co-immunoprecipitation, localization and topology experiments","pmids":["24782309"],"confidence":"Medium","gaps":["Single lab","Functional consequence of LRRC8B in the complex not shown","Stoichiometry undetermined"]},{"year":2014,"claim":"Establishing the channel context, LRRC8A was shown to be indispensable for VRAC and to require at least one of LRRC8B-E partners, defining LRRC8B as one of the complementary subunits that can complete a functional anion channel.","evidence":"siRNA knockdown and radiotracer osmolyte-release assays in primary rat astrocytes","pmids":["25172945"],"confidence":"High","gaps":["Specific contribution of LRRC8B versus other complementary subunits not resolved","No structural model"]},{"year":2017,"claim":"To define LRRC8B's functional weight within VRAC, RNAi dissection showed LRRC8B silencing alone does not impair osmolyte release while LRRC8C/D loss does, placing LRRC8B as a complementary but non-dominant subunit.","evidence":"RNAi knockdown and radiotracer release assays in primary rat astrocytes","pmids":["28833202"],"confidence":"Medium","gaps":["Negative result for LRRC8B may reflect redundancy","Single lab","Channel composition in LRRC8B-knockdown cells not characterized"]},{"year":2017,"claim":"A distinct mechanistic role was proposed by overexpression and knockdown experiments indicating LRRC8B can act as an ER Ca2+ leak channel that modulates ER store content and store-operated Ca2+ entry.","evidence":"Overexpression/knockdown in HEK293 cells with intracellular Ca2+ measurements, thapsigargin block and IP3 stimulation","pmids":["28972132"],"confidence":"Medium","gaps":["Single lab","ER localization of an endogenous channel not reconstituted","Relationship to plasma-membrane VRAC role unclear"]},{"year":2017,"claim":"Addressing how LRRC8 channels sense redox state, electrophysiology showed subunit-dependent oxidation sensitivity, but LRRC8B-containing heteromers were not specifically tested, leaving its redox behavior undefined.","evidence":"Electrophysiology of tagged LRRC8 heteromers with chloramine-T and tert-butyl hydroperoxide","pmids":["28841766"],"confidence":"Medium","gaps":["LRRC8B heteromers not assayed for oxidation","Cysteine residues responsible not mapped for LRRC8B"]},{"year":2019,"claim":"Whether LRRC8B is part of native channels rather than an overexpression artifact was settled by quantitative immunoblotting and endogenous LRRC8A immunoprecipitation, confirming LRRC8B as a bona fide partner present at generally low, tissue-specific levels.","evidence":"Quantitative immunoblotting with recombinant calibration and IP of endogenous LRRC8A from mouse cells and tissues","pmids":["31771171"],"confidence":"Medium","gaps":["Single lab","Functional output of native LRRC8B-containing complexes not measured","Subunit stoichiometry per hexamer unknown"]},{"year":2022,"claim":"Extending tissue context, LRRC8B was shown to co-localize with LRRC8A at proximal-tubule basolateral membranes where LRRC8A/D VRACs mediate organic-compound exit, though LRRC8B's specific functional contribution there was not isolated.","evidence":"Epitope-tagged knock-in mice, immunohistochemistry, conditional/constitutive knockouts, metabolomics","pmids":["35777784"],"confidence":"Medium","gaps":["No LRRC8B-specific knockout in tubules","Co-localization does not establish transport role"]},{"year":2023,"claim":"The structural basis of how complementary subunits like LRRC8B shape channel architecture was revealed by cryo-EM of LRRC8A:C heterohexamers, showing heterotypic LRR-domain interactions and lipid pore gating as general assembly principles.","evidence":"Single-particle cryo-EM with fiducial tagging and electrophysiology","pmids":["36928458"],"confidence":"High","gaps":["No LRRC8B-containing structure solved","LRRC8B-specific pore properties unknown"]},{"year":2025,"claim":"In the vasculature, reciprocal co-IP from knock-in mice defined LRRC8A/B/C as the predominant endothelial heteromer with co-dependent subunit expression, linking LRRC8B-containing VRAC to mechanoresponsive AKT-eNOS signaling and vascular tone.","evidence":"Co-IP from knock-in mice, endothelium-specific knockout/knockdown, electrophysiology, pressure myography, angiotensin hypertension model (one report a preprint)","pmids":["40894750","41636028"],"confidence":"Medium","gaps":["LRRC8B-specific functional role not separated from LRRC8A/C","Single lab","Mechanism coupling channel activity to AKT-eNOS not resolved"]},{"year":2025,"claim":"A refined view of LRRC8B's structural role in astrocytes came from RNAi showing that LRRC8B knockdown partially rescues glutamate-analogue release in LRRC8C/D-deficient cells, consistent with a non-determinant structural contribution.","evidence":"RNAi knockdown in primary mouse astrocytes, radiotracer release assays, qPCR, RNA-seq (preprint)","pmids":["40766626"],"confidence":"Low","gaps":["Preprint, not peer-reviewed","LRRC8B role inferred from double-knockdown rescue","Mechanism of rescue unknown"]},{"year":2025,"claim":"Whether LRRC8B is required for immune-cell ontogeny was tested by constitutive knockout, which showed normal T and B cell development and established LRRC8B as dispensable for lymphocyte development in vivo.","evidence":"Constitutive LRRC8B knockout mice analyzed for T and B cell development","pmids":["41419196"],"confidence":"Medium","gaps":["Negative result; possible redundancy with other paralogs not excluded","Other immune or non-immune phenotypes not assessed"]},{"year":null,"claim":"It remains unknown what unique functional contribution LRRC8B makes to native VRAC complexes distinct from other complementary subunits, and how its proposed ER Ca2+-leak role mechanistically relates to its plasma-membrane channel role.","evidence":"","pmids":[],"confidence":"Low","gaps":["No LRRC8B-containing channel structure","No demonstrated LRRC8B-specific permeability property","Reconciliation of ER versus plasma-membrane functions unresolved"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0005215","term_label":"transporter activity","supporting_discovery_ids":[2,3,4]},{"term_id":"GO:0005198","term_label":"structural molecule activity","supporting_discovery_ids":[6,8]}],"localization":[{"term_id":"GO:0005886","term_label":"plasma membrane","supporting_discovery_ids":[1,7]},{"term_id":"GO:0005783","term_label":"endoplasmic reticulum","supporting_discovery_ids":[4]}],"pathway":[{"term_id":"R-HSA-382551","term_label":"Transport of small molecules","supporting_discovery_ids":[2,3,7]},{"term_id":"R-HSA-162582","term_label":"Signal Transduction","supporting_discovery_ids":[10]}],"complexes":["VRAC (LRRC8 heterohexamer)"],"partners":["LRRC8A","LRRC8C","LRRC8D","LRRC8E"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"Q6P9F7","full_name":"Volume-regulated anion channel subunit LRRC8B","aliases":["Leucine-rich repeat-containing protein 8B","T-cell activation leucine repeat-rich protein","TA-LRRP"],"length_aa":803,"mass_kda":92.4,"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. 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)","subcellular_location":"Cell membrane; Endoplasmic reticulum membrane","url":"https://www.uniprot.org/uniprotkb/Q6P9F7/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/LRRC8B","classification":"Not Classified","n_dependent_lines":23,"n_total_lines":1208,"dependency_fraction":0.01903973509933775},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/LRRC8B","total_profiled":1310},"omim":[{"mim_id":"612888","title":"LEUCINE-RICH REPEAT-CONTAINING PROTEIN 8B; LRRC8B","url":"https://www.omim.org/entry/612888"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"","locations":[],"tissue_specificity":"Tissue enhanced","tissue_distribution":"Detected in all","driving_tissues":[{"tissue":"brain","ntpm":20.9}],"url":"https://www.proteinatlas.org/search/LRRC8B"},"hgnc":{"alias_symbol":["TA-LRRP","KIAA0231"],"prev_symbol":[]},"alphafold":{"accession":"Q6P9F7","domains":[{"cath_id":"1.20.1440","chopping":"3-73_97-142_255-338","consensus_level":"medium","plddt":84.8694,"start":3,"end":338}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q6P9F7","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q6P9F7-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q6P9F7-F1-predicted_aligned_error_v6.png","plddt_mean":81.0},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=LRRC8B","jax_strain_url":"https://www.jax.org/strain/search?query=LRRC8B"},"sequence":{"accession":"Q6P9F7","fasta_url":"https://rest.uniprot.org/uniprotkb/Q6P9F7.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q6P9F7/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q6P9F7"}},"corpus_meta":[{"pmid":"30045751","id":"PMC_30045751","title":"DNA methylation analysis on purified neurons and glia dissects age and Alzheimer's disease-specific changes in the human cortex.","date":"2018","source":"Epigenetics & chromatin","url":"https://pubmed.ncbi.nlm.nih.gov/30045751","citation_count":167,"is_preprint":false},{"pmid":"25172945","id":"PMC_25172945","title":"LRRC8A protein is indispensable for swelling-activated and ATP-induced release of excitatory amino acids in rat astrocytes.","date":"2014","source":"The Journal of physiology","url":"https://pubmed.ncbi.nlm.nih.gov/25172945","citation_count":113,"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":"24782309","id":"PMC_24782309","title":"The protein synthesis inhibitor blasticidin s enters mammalian cells via leucine-rich repeat-containing protein 8D.","date":"2014","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/24782309","citation_count":67,"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":"36928458","id":"PMC_36928458","title":"Structural basis for assembly and lipid-mediated gating of LRRC8A:C volume-regulated anion channels.","date":"2023","source":"Nature structural & molecular biology","url":"https://pubmed.ncbi.nlm.nih.gov/36928458","citation_count":37,"is_preprint":false},{"pmid":"27688432","id":"PMC_27688432","title":"Leucine-rich repeat containing protein LRRC8A is essential for swelling-activated Cl- currents and embryonic development in zebrafish.","date":"2016","source":"Physiological reports","url":"https://pubmed.ncbi.nlm.nih.gov/27688432","citation_count":27,"is_preprint":false},{"pmid":"32442571","id":"PMC_32442571","title":"Volume-regulated anion channel as a novel cancer therapeutic target.","date":"2020","source":"International journal of biological macromolecules","url":"https://pubmed.ncbi.nlm.nih.gov/32442571","citation_count":26,"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":"31771171","id":"PMC_31771171","title":"Absolute Protein Amounts and Relative Abundance of Volume-regulated Anion Channel (VRAC) LRRC8 Subunits in Cells and Tissues Revealed by Quantitative Immunoblotting.","date":"2019","source":"International journal of molecular sciences","url":"https://pubmed.ncbi.nlm.nih.gov/31771171","citation_count":19,"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":"28121479","id":"PMC_28121479","title":"Cisplatin activates volume sensitive LRRC8 channel mediated currents in Xenopus oocytes.","date":"2017","source":"Channels (Austin, Tex.)","url":"https://pubmed.ncbi.nlm.nih.gov/28121479","citation_count":16,"is_preprint":false},{"pmid":"35054564","id":"PMC_35054564","title":"The Role of Chloride Channels in the Multidrug Resistance.","date":"2021","source":"Membranes","url":"https://pubmed.ncbi.nlm.nih.gov/35054564","citation_count":12,"is_preprint":false},{"pmid":"39709525","id":"PMC_39709525","title":"Recent advances in the structure, function and regulation of the volume-regulated anion channels and their role in immunity.","date":"2024","source":"The Journal of physiology","url":"https://pubmed.ncbi.nlm.nih.gov/39709525","citation_count":12,"is_preprint":false},{"pmid":"35563558","id":"PMC_35563558","title":"VI-116, A Novel Potent Inhibitor of VRAC with Minimal Effect on ANO1.","date":"2022","source":"International journal of molecular sciences","url":"https://pubmed.ncbi.nlm.nih.gov/35563558","citation_count":9,"is_preprint":false},{"pmid":"36833283","id":"PMC_36833283","title":"Study on the Association between LRRC8B Gene InDel and Sheep Body Conformation Traits.","date":"2023","source":"Genes","url":"https://pubmed.ncbi.nlm.nih.gov/36833283","citation_count":5,"is_preprint":false},{"pmid":"39977537","id":"PMC_39977537","title":"Recent advances in structural characterization of volume-regulated anion channels (VRACs).","date":"2025","source":"The Journal of physiology","url":"https://pubmed.ncbi.nlm.nih.gov/39977537","citation_count":5,"is_preprint":false},{"pmid":"39798592","id":"PMC_39798592","title":"Genetic parameters and single-step genome-wide association analysis for trematode (Fasciola hepatica and Calicophoron/Paramphistomum spp.) infections in German dairy cows.","date":"2025","source":"Infection, genetics and evolution : journal of molecular epidemiology and evolutionary genetics in infectious diseases","url":"https://pubmed.ncbi.nlm.nih.gov/39798592","citation_count":5,"is_preprint":false},{"pmid":"39833228","id":"PMC_39833228","title":"Brain gliomas new transcriptomic discoveries from differentially expressed genes to therapeutic targets.","date":"2025","source":"Scientific reports","url":"https://pubmed.ncbi.nlm.nih.gov/39833228","citation_count":4,"is_preprint":false},{"pmid":"41636028","id":"PMC_41636028","title":"Endothelial LRRC8C Associates With LRRC8A and LRRC8B to Regulate Vascular Reactivity and Blood Pressure.","date":"2026","source":"Hypertension (Dallas, Tex. : 1979)","url":"https://pubmed.ncbi.nlm.nih.gov/41636028","citation_count":2,"is_preprint":false},{"pmid":"40894750","id":"PMC_40894750","title":"Endothelial LRRC8C associates with LRRC8A and LRRC8B to regulate vascular reactivity and blood pressure.","date":"2025","source":"bioRxiv : the preprint server for biology","url":"https://pubmed.ncbi.nlm.nih.gov/40894750","citation_count":2,"is_preprint":false},{"pmid":"40766626","id":"PMC_40766626","title":"Subunit-specific roles of LRRC8 proteins in determining glutamate permeability of astrocytic volume-regulated anion channels.","date":"2025","source":"bioRxiv : the preprint server for biology","url":"https://pubmed.ncbi.nlm.nih.gov/40766626","citation_count":1,"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},{"pmid":"41544563","id":"PMC_41544563","title":"Genome-wide interaction analysis of long-term trihalomethane exposure in drinking water and colorectal cancer risk in a Spanish Multicenter Case-Control Study (MCC-Spain).","date":"2026","source":"Environment international","url":"https://pubmed.ncbi.nlm.nih.gov/41544563","citation_count":0,"is_preprint":false},{"pmid":null,"id":"bio_10.1101_2024.11.24.625074","title":"Assembly and lipid-gating of LRRC8A:D volume-regulated anion channels","date":"2024-11-26","source":"bioRxiv","url":"https://doi.org/10.1101/2024.11.24.625074","citation_count":0,"is_preprint":true}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":16597,"output_tokens":3372,"usd":0.050186,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":10720,"output_tokens":3896,"usd":0.0755,"stage2_stop_reason":"end_turn"},"total_usd":0.125686,"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\": \"LRRC8B (TA-LRRP) was identified as a member of a novel family of leucine-rich repeat proteins. The predicted structure includes 16 extracellular leucine-rich repeats and four transmembrane regions, similar to LRRC8A and other family members.\",\n      \"method\": \"Sequence analysis and structural prediction of novel LRRC8-like genes\",\n      \"journal\": \"FEBS letters\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 4 / Weak — computational/bioinformatic prediction only, no functional experiments on LRRC8B specifically\",\n      \"pmids\": [\"15094057\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"LRRC8D interacts with LRRC8A, LRRC8B, and LRRC8C, as demonstrated by co-immunoprecipitation. LRRC8 proteins including LRRC8B localize to the plasma membrane with defined topology, supporting roles in solute transport.\",\n      \"method\": \"Co-immunoprecipitation, localization and topology experiments\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 / Moderate — direct co-IP establishing LRRC8B as an interaction partner of LRRC8D, with localization data, single lab\",\n      \"pmids\": [\"24782309\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"LRRC8A is an indispensable component of the volume-regulated anion channel (VRAC), which is a heteromeric complex requiring LRRC8A plus at least one of LRRC8B-E subunits to mediate swelling-activated Cl- currents and organic osmolyte release.\",\n      \"method\": \"siRNA knockdown, radiotracer assays, quantitative RT-PCR in primary rat astrocytes\",\n      \"journal\": \"The Journal of physiology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — reciprocal functional knockdown with multiple substrate readouts, independently replicated across multiple labs\",\n      \"pmids\": [\"25172945\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"LRRC8B is a component of heteromeric VRAC complexes in astrocytes. Knockdown of LRRC8B alone did not significantly alter swelling-activated release of charged (d-aspartate) or uncharged (taurine, myo-inositol) osmolytes, but combined silencing of LRRC8C+LRRC8D strongly inhibited all osmolyte release, placing LRRC8B as a complementary but non-dominant subunit.\",\n      \"method\": \"RNAi knockdown, radiotracer assays in primary rat astrocytes\",\n      \"journal\": \"The Journal of physiology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — clean RNAi with multiple substrate readouts, single lab, LRRC8B-specific effect was largely negative (non-dominant role)\",\n      \"pmids\": [\"28833202\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"LRRC8B overexpression in HEK293 cells reduced ER Ca2+ levels and increased ER Ca2+ leak. LRRC8B-overexpressing cells showed reduced IP3-stimulated Ca2+ release and enhanced store-operated Ca2+ entry, while LRRC8B-knockdown cells showed slower TG-induced ER Ca2+ depletion. These data establish LRRC8B as a Ca2+ leak channel in the ER membrane.\",\n      \"method\": \"Overexpression and siRNA knockdown in HEK293 cells, intracellular Ca2+ measurements, thapsigargin block experiments, IP3 stimulation assays\",\n      \"journal\": \"Journal of cell science\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — both gain-of-function and loss-of-function approaches with multiple readouts, single lab\",\n      \"pmids\": [\"28972132\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"LRRC8A-LRRC8E heteromeric channels are activated by oxidation of intracellular cysteines, whereas LRRC8A-LRRC8C and LRRC8A-LRRC8D heteromers are inhibited by oxidation. The subunit-dependent oxidation sensitivity shows LRRC8 channel proteins are directly modulated by ROS. LRRC8B-containing heteromers were not specifically tested for oxidation sensitivity in this study.\",\n      \"method\": \"Electrophysiology of fluorescently tagged LRRC8 heteromers expressed in cells, treatment with chloramine-T and tert-butyl hydroperoxide\",\n      \"journal\": \"The Journal of physiology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — direct electrophysiology with chemical probes, single lab; LRRC8B specifically not characterized for oxidation\",\n      \"pmids\": [\"28841766\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"Immunoprecipitation of LRRC8A co-precipitates LRRC8B (along with LRRC8C, D, E), confirming LRRC8B is a bona fide partner in endogenous VRAC heterohexameric complexes. Quantitative immunoblotting revealed tissue-specific expression patterns of LRRC8B with generally low absolute amounts.\",\n      \"method\": \"Quantitative immunoblotting using recombinant protein calibration, immunoprecipitation of endogenous LRRC8A from mouse cell lines and tissues\",\n      \"journal\": \"International journal of molecular sciences\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — co-IP from endogenous proteins with quantitative calibration, single lab\",\n      \"pmids\": [\"31771171\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"LRRC8A and LRRC8B (along with LRRC8D) are expressed in basolateral membranes of proximal tubules in the kidney. Constitutive deletion of LRRC8D and conditional deletion of LRRC8A in proximal tubules cause proximal tubular injury and mild Fanconi-like symptoms, establishing that LRRC8A/D-containing VRACs are required for basolateral exit of organic compounds in proximal tubules. LRRC8B co-localizes with LRRC8A at basolateral membranes.\",\n      \"method\": \"Epitope-tagged knock-in mice, immunohistochemistry, constitutive and conditional knockout mouse models, urine/serum analysis, metabolomics\",\n      \"journal\": \"Journal of the American Society of Nephrology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — genetic models with functional readouts in vivo, but LRRC8B-specific functional contribution not directly demonstrated (co-localization established, not specific knockout)\",\n      \"pmids\": [\"35777784\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"Cryo-EM structures of heterohexameric LRRC8A:C channels revealed the structural basis for heteromeric VRAC assembly, including heterotypic LRR domain interactions that displace subunits and lipid gating in the pore. While this study focused on LRRC8A:C, the findings establish general principles of how complementary LRRC8 subunits (including LRRC8B) determine channel architecture through LRR domain interactions.\",\n      \"method\": \"Single-particle cryo-EM with fiducial-tagging strategy, electrophysiology\",\n      \"journal\": \"Nature structural & molecular biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — high-resolution cryo-EM structures with functional validation by electrophysiology, reveals general mechanism for heteromeric subunit assembly relevant to LRRC8B\",\n      \"pmids\": [\"36928458\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"In endothelial cells, co-immunoprecipitation from Lrrc8a-3xFlag knock-in mice and Lrrc8c-HA knock-in mice revealed enrichment of LRRC8A/B/C heteromers as the predominant endothelial LRRC8 complex. Lrrc8a/b/c depletion showed co-dependent expression of LRRC8A, LRRC8B, and LRRC8C (but not LRRC8D), establishing LRRC8B as a structural component of the endothelial VRAC complex.\",\n      \"method\": \"Co-immunoprecipitation from knock-in mice, endothelium-specific knockout/knockdown, electrophysiology, pressure myography\",\n      \"journal\": \"bioRxiv (preprint)\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — reciprocal co-IP from knock-in mice with functional readouts; preprint, not yet peer-reviewed\",\n      \"pmids\": [\"40894750\"],\n      \"is_preprint\": true\n    },\n    {\n      \"year\": 2026,\n      \"finding\": \"Co-immunoprecipitation from endothelium-specific Lrrc8a-3xFlag overexpression mice confirmed LRRC8A/B/C form the endothelial LRRC8 heteromeric complex. LRRC8B shows co-dependent expression with LRRC8A and LRRC8C in endothelium (but not LRRC8D). LRRC8B is part of the mechanoresponsive endothelial VRAC that regulates AKT-eNOS signaling and vascular tone.\",\n      \"method\": \"Co-immunoprecipitation from epitope-tagged knock-in mice, endothelium-specific knockout, electrophysiology, pressure myography, angiotensin-induced hypertension model\",\n      \"journal\": \"Hypertension\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — reciprocal co-IP with in vivo functional readouts, single lab, LRRC8B-specific functional role not independently demonstrated from LRRC8A/C\",\n      \"pmids\": [\"41636028\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"LRRC8B silencing alone did not reduce swelling-activated glutamate-analogue (D-[3H]aspartate) release from astrocytes, but LRRC8B knockdown partially rescued glutamate release in LRRC8C- or LRRC8D-knockdown cells, suggesting LRRC8B has a possible structural role in astrocytic VRACs without being a primary determinant of glutamate permeability.\",\n      \"method\": \"RNAi knockdown in primary mouse astrocytes, radiotracer release assays, qPCR, RNA-seq\",\n      \"journal\": \"bioRxiv (preprint)\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — single lab, preprint, LRRC8B-specific role inferred from partial rescue in double-knockdown conditions\",\n      \"pmids\": [\"40766626\"],\n      \"is_preprint\": true\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"Disruption of LRRC8B in mice had no discernible effect on T or B cell development, establishing that LRRC8B is not required for lymphocyte development in vivo.\",\n      \"method\": \"Constitutive LRRC8B knockout mice analyzed for T and B cell development\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — in vivo genetic loss-of-function with defined immunological readout; negative result\",\n      \"pmids\": [\"41419196\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"LRRC8B is a complementary (non-essential) subunit of the heterohexameric volume-regulated anion channel (VRAC), assembling with the obligate LRRC8A subunit and other LRRC8 paralogs; in endothelial cells it forms a predominant LRRC8A/B/C complex that supports AKT-eNOS signaling and vascular tone, while in astrocytes its silencing alone does not substantially alter swelling-activated organic osmolyte release; additionally, overexpression studies indicate LRRC8B can function as an ER Ca2+ leak channel, and LRRC8B knockout mice show no defect in lymphocyte development.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"LRRC8B is a complementary, non-obligate subunit of the heterohexameric volume-regulated anion channel (VRAC), assembling with the indispensable LRRC8A subunit and other LRRC8 paralogs (C, D, E) into endogenous channel complexes [#2, #6]. Co-immunoprecipitation of endogenous LRRC8A consistently recovers LRRC8B as a bona fide partner, and cryo-EM of LRRC8A:C heterohexamers defines how complementary subunits assemble through heterotypic leucine-rich-repeat domain interactions and lipid-dependent pore gating [#6, #8]. LRRC8B occupies a structural but non-dominant role: silencing LRRC8B alone does not appreciably alter swelling-activated release of charged or uncharged osmolytes from astrocytes, in contrast to the strong suppression seen with combined LRRC8C/D loss [#3]. In endothelial cells, LRRC8B is part of a predominant LRRC8A/B/C complex whose subunits are co-dependent for expression, and this mechanoresponsive VRAC regulates AKT-eNOS signaling and vascular tone [#10]. Beyond its role within VRAC, overexpression and knockdown studies place LRRC8B in the ER membrane as a Ca2+ leak channel, where it lowers ER Ca2+ stores and shapes store-operated Ca2+ entry [#4]. Constitutive LRRC8B knockout mice show no defect in T or B cell development, indicating it is dispensable for lymphocyte development in vivo [#12].\",\n  \"teleology\": [\n    {\n      \"year\": 2004,\n      \"claim\": \"Before any functional data, the question was whether LRRC8B belonged to a coherent protein family with a shared architecture; sequence analysis established it as a member of the LRRC8 family with extracellular leucine-rich repeats and four transmembrane regions.\",\n      \"evidence\": \"Sequence analysis and structural prediction of novel LRRC8-like genes\",\n      \"pmids\": [\"15094057\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"Computational prediction only\", \"No functional assay on LRRC8B\", \"Topology and membrane targeting not experimentally verified\"]\n    },\n    {\n      \"year\": 2014,\n      \"claim\": \"The open question of whether LRRC8B physically associates with other family members was answered by showing it co-immunoprecipitates with LRRC8D and localizes to the plasma membrane with a defined topology, establishing it as a candidate transport-complex subunit.\",\n      \"evidence\": \"Co-immunoprecipitation, localization and topology experiments\",\n      \"pmids\": [\"24782309\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Single lab\", \"Functional consequence of LRRC8B in the complex not shown\", \"Stoichiometry undetermined\"]\n    },\n    {\n      \"year\": 2014,\n      \"claim\": \"Establishing the channel context, LRRC8A was shown to be indispensable for VRAC and to require at least one of LRRC8B-E partners, defining LRRC8B as one of the complementary subunits that can complete a functional anion channel.\",\n      \"evidence\": \"siRNA knockdown and radiotracer osmolyte-release assays in primary rat astrocytes\",\n      \"pmids\": [\"25172945\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Specific contribution of LRRC8B versus other complementary subunits not resolved\", \"No structural model\"]\n    },\n    {\n      \"year\": 2017,\n      \"claim\": \"To define LRRC8B's functional weight within VRAC, RNAi dissection showed LRRC8B silencing alone does not impair osmolyte release while LRRC8C/D loss does, placing LRRC8B as a complementary but non-dominant subunit.\",\n      \"evidence\": \"RNAi knockdown and radiotracer release assays in primary rat astrocytes\",\n      \"pmids\": [\"28833202\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Negative result for LRRC8B may reflect redundancy\", \"Single lab\", \"Channel composition in LRRC8B-knockdown cells not characterized\"]\n    },\n    {\n      \"year\": 2017,\n      \"claim\": \"A distinct mechanistic role was proposed by overexpression and knockdown experiments indicating LRRC8B can act as an ER Ca2+ leak channel that modulates ER store content and store-operated Ca2+ entry.\",\n      \"evidence\": \"Overexpression/knockdown in HEK293 cells with intracellular Ca2+ measurements, thapsigargin block and IP3 stimulation\",\n      \"pmids\": [\"28972132\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Single lab\", \"ER localization of an endogenous channel not reconstituted\", \"Relationship to plasma-membrane VRAC role unclear\"]\n    },\n    {\n      \"year\": 2017,\n      \"claim\": \"Addressing how LRRC8 channels sense redox state, electrophysiology showed subunit-dependent oxidation sensitivity, but LRRC8B-containing heteromers were not specifically tested, leaving its redox behavior undefined.\",\n      \"evidence\": \"Electrophysiology of tagged LRRC8 heteromers with chloramine-T and tert-butyl hydroperoxide\",\n      \"pmids\": [\"28841766\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"LRRC8B heteromers not assayed for oxidation\", \"Cysteine residues responsible not mapped for LRRC8B\"]\n    },\n    {\n      \"year\": 2019,\n      \"claim\": \"Whether LRRC8B is part of native channels rather than an overexpression artifact was settled by quantitative immunoblotting and endogenous LRRC8A immunoprecipitation, confirming LRRC8B as a bona fide partner present at generally low, tissue-specific levels.\",\n      \"evidence\": \"Quantitative immunoblotting with recombinant calibration and IP of endogenous LRRC8A from mouse cells and tissues\",\n      \"pmids\": [\"31771171\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Single lab\", \"Functional output of native LRRC8B-containing complexes not measured\", \"Subunit stoichiometry per hexamer unknown\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Extending tissue context, LRRC8B was shown to co-localize with LRRC8A at proximal-tubule basolateral membranes where LRRC8A/D VRACs mediate organic-compound exit, though LRRC8B's specific functional contribution there was not isolated.\",\n      \"evidence\": \"Epitope-tagged knock-in mice, immunohistochemistry, conditional/constitutive knockouts, metabolomics\",\n      \"pmids\": [\"35777784\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No LRRC8B-specific knockout in tubules\", \"Co-localization does not establish transport role\"]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"The structural basis of how complementary subunits like LRRC8B shape channel architecture was revealed by cryo-EM of LRRC8A:C heterohexamers, showing heterotypic LRR-domain interactions and lipid pore gating as general assembly principles.\",\n      \"evidence\": \"Single-particle cryo-EM with fiducial tagging and electrophysiology\",\n      \"pmids\": [\"36928458\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"No LRRC8B-containing structure solved\", \"LRRC8B-specific pore properties unknown\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"In the vasculature, reciprocal co-IP from knock-in mice defined LRRC8A/B/C as the predominant endothelial heteromer with co-dependent subunit expression, linking LRRC8B-containing VRAC to mechanoresponsive AKT-eNOS signaling and vascular tone.\",\n      \"evidence\": \"Co-IP from knock-in mice, endothelium-specific knockout/knockdown, electrophysiology, pressure myography, angiotensin hypertension model (one report a preprint)\",\n      \"pmids\": [\"40894750\", \"41636028\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"LRRC8B-specific functional role not separated from LRRC8A/C\", \"Single lab\", \"Mechanism coupling channel activity to AKT-eNOS not resolved\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"A refined view of LRRC8B's structural role in astrocytes came from RNAi showing that LRRC8B knockdown partially rescues glutamate-analogue release in LRRC8C/D-deficient cells, consistent with a non-determinant structural contribution.\",\n      \"evidence\": \"RNAi knockdown in primary mouse astrocytes, radiotracer release assays, qPCR, RNA-seq (preprint)\",\n      \"pmids\": [\"40766626\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"Preprint, not peer-reviewed\", \"LRRC8B role inferred from double-knockdown rescue\", \"Mechanism of rescue unknown\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Whether LRRC8B is required for immune-cell ontogeny was tested by constitutive knockout, which showed normal T and B cell development and established LRRC8B as dispensable for lymphocyte development in vivo.\",\n      \"evidence\": \"Constitutive LRRC8B knockout mice analyzed for T and B cell development\",\n      \"pmids\": [\"41419196\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Negative result; possible redundancy with other paralogs not excluded\", \"Other immune or non-immune phenotypes not assessed\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"It remains unknown what unique functional contribution LRRC8B makes to native VRAC complexes distinct from other complementary subunits, and how its proposed ER Ca2+-leak role mechanistically relates to its plasma-membrane channel role.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"No LRRC8B-containing channel structure\", \"No demonstrated LRRC8B-specific permeability property\", \"Reconciliation of ER versus plasma-membrane functions unresolved\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0005215\", \"supporting_discovery_ids\": [2, 3, 4]},\n      {\"term_id\": \"GO:0005198\", \"supporting_discovery_ids\": [6, 8]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005886\", \"supporting_discovery_ids\": [1, 7]},\n      {\"term_id\": \"GO:0005783\", \"supporting_discovery_ids\": [4]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-382551\", \"supporting_discovery_ids\": [2, 3, 7]},\n      {\"term_id\": \"R-HSA-162582\", \"supporting_discovery_ids\": [10]}\n    ],\n    \"complexes\": [\"VRAC (LRRC8 heterohexamer)\"],\n    \"partners\": [\"LRRC8A\", \"LRRC8C\", \"LRRC8D\", \"LRRC8E\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":6,"faith_total":6,"faith_pct":100.0}}