{"gene":"CRB3","run_date":"2026-06-09T22:57:19","timeline":{"discoveries":[{"year":2004,"finding":"CRB3 directly binds Par6 via its C-terminal ERLI motif (PDZ-binding domain), and overexpression of CRB3 slows development of functional tight junctions in MDCK cells in a manner dependent on this ERLI domain.","method":"Direct binding assay, domain deletion/chimera overexpression in MDCK cells, tight junction permeability assays","journal":"Molecular biology of the cell","confidence":"High","confidence_rationale":"Tier 1–2 / Moderate — direct interaction demonstrated with binding assay and domain-specific mutagenesis (ERLI motif), functional phenotype confirmed in epithelial cells with chimeric constructs","pmids":["14718572"],"is_preprint":false},{"year":2013,"finding":"The WD40 protein Morg1 directly binds Par6 and facilitates apical targeting of the Par6-aPKC complex to CRB3 at the apical membrane; this interaction is reinforced by Cdc42. Depletion of Morg1 disrupts tight junction development and cyst formation, rescued by forced apical targeting of aPKC.","method":"Co-IP, epistasis (Morg1 depletion + forced apical aPKC targeting), 3D cyst assay, MDCK cells","journal":"The Journal of cell biology","confidence":"High","confidence_rationale":"Tier 2 / Moderate — reciprocal Co-IP, genetic epistasis rescue experiment, two orthogonal functional assays (monolayer TJ and 3D cyst)","pmids":["23439680"],"is_preprint":false},{"year":2016,"finding":"CRB3 interacts with actin-regulatory proteins Arp3 (branched actin polymerization) and Eps8 (barbed-end capping/bundling) in Sertoli cells. CRB3 knockdown disrupts actin microfilament organization, truncating and branching actin, which destabilizes TJ- and basal ES-protein complexes at the blood-testis barrier, and impairs spermatid/phagosome transport and spermatid polarity in vivo.","method":"Co-IP (binding partners Arp3 and Eps8), RNAi knockdown in Sertoli cells with TJ-permeability barrier assay, in vivo CRB3 KD via jetPEI transfection with histological readouts","journal":"Scientific reports","confidence":"Medium","confidence_rationale":"Tier 2–3 / Moderate — Co-IP for binding partners, RNAi with functional TJ assay, and in vivo knockdown with spermatid phenotype; single lab","pmids":["27358069"],"is_preprint":false},{"year":2016,"finding":"CRB3, localized at the tips of the peripheral myelin sheath, activates the Hippo pathway to inhibit YAP transcriptional activity, thereby limiting myelin elongation. Loss of CRB3-mediated Hippo activation results in decreased nuclear YAP and shorter myelin internodes in dystrophic mice.","method":"In vivo localization (immunofluorescence), genetic mouse model (Dy2j/2j), YAP nuclear activity assays, functional nerve conduction measurements","journal":"Nature communications","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — in vivo localization linked to functional pathway (Hippo/YAP) with genetic mouse model and physiological readout; single lab","pmids":["27435623"],"is_preprint":false},{"year":2017,"finding":"CRB3 acts as an upstream activator of the Hippo pathway in mammary epithelial cells by recruiting Kibra and/or FRMD6, leading to activation of LATS1/2 kinases, YAP inactivation, and contact inhibition of proliferation.","method":"Co-immunoprecipitation (CRB3 with Kibra/FRMD6), CRB3 overexpression and knockdown with Hippo pathway readouts (LATS phosphorylation, YAP localization), proliferation and apoptosis assays, in vivo tumor suppression","journal":"Cell death & disease","confidence":"Medium","confidence_rationale":"Tier 2–3 / Moderate — Co-IP for Kibra/FRMD6 interaction, KD/OE with pathway readouts; single lab","pmids":["28079891"],"is_preprint":false},{"year":2016,"finding":"MUC1-C associates with ZEB1 on the CRB3 promoter to repress CRB3 transcription in triple-negative breast cancer cells, thereby suppressing CRB3-driven Hippo pathway activation (LATS1/2), leading to YAP dephosphorylation/activation, YAP/β-catenin complex formation, and MYC induction.","method":"ChIP (MUC1-C/ZEB1 on CRB3 promoter), CRB3 mRNA/protein measurement upon MUC1-C targeting, LATS1 phosphorylation assay, YAP localization, Co-IP (YAP/β-catenin), MYC expression","journal":"Molecular cancer research : MCR","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — ChIP for promoter occupancy, multiple downstream pathway readouts; single lab","pmids":["27658423"],"is_preprint":false},{"year":2017,"finding":"CRB3 downregulation in MCF-10A cells induces EMT, activates TAZ and β-catenin signaling, and confers cancer stem cell properties; TAZ and β-catenin activation was sufficient to recapitulate the CSC phenotype caused by CRB3 loss.","method":"CRB3 knockdown in MCF-10A, TAZ/β-catenin activation assays, sphere formation and CSC marker assays, epistasis (TAZ/β-catenin activation phenocopy)","journal":"Oncogenesis","confidence":"Medium","confidence_rationale":"Tier 2–3 / Moderate — KD with multiple functional readouts and pathway activation, epistasis by activation of TAZ/β-catenin; single lab","pmids":["28436991"],"is_preprint":false},{"year":2018,"finding":"CRB3 overexpression drives proliferation in mammary epithelial cells through increased secretion of amphiregulin (AREG), in a manner dependent on the FERM-binding domain (FBD) but not the PDZ-binding domain of CRB3. EPB41L4B was identified as an essential FBD-dependent mediator of CRB3-driven proliferation and associated changes in endocytic trafficking.","method":"CRB3 domain deletion constructs (FBD vs PDZ-binding domain), AREG secretion assay, endosome size/number quantification, EPB41L4B knockdown, 3D acini culture assay","journal":"PloS one","confidence":"Medium","confidence_rationale":"Tier 2–3 / Moderate — domain-specific mutagenesis/deletion, downstream mediator knockdown, multiple orthogonal assays; single lab","pmids":["30440051"],"is_preprint":false},{"year":2022,"finding":"METTL3-mediated m6A methylation of CRB3 mRNA promotes its degradation via YTHDF2 binding. METTL3 knockdown reduces m6A on CRB3 mRNA, increases CRB3 expression, and activates the Hippo pathway (reducing nuclear YAP); these effects are reversed by CRB3 knockdown, placing CRB3 downstream of METTL3/YTHDF2 in an m6A-CRB3-Hippo axis.","method":"m6A epitranscriptomic microarray, MeRIP-qPCR, RNA stability assay, luciferase reporter, RNA immunoprecipitation (YTHDF2-CRB3 mRNA), METTL3/YTHDF2 knockdown with CRB3 mRNA/protein readouts, epistasis (CRB3 KD reversal of Hippo activation)","journal":"Journal of experimental & clinical cancer research : CR","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — multiple orthogonal RNA-level assays (MeRIP, RIP, luciferase, stability), epistasis experiment; single lab","pmids":["35012593"],"is_preprint":false},{"year":2023,"finding":"CRB3 localizes to the basal body and is trafficked via Rab11-positive endosomes. CRB3 interacts with Rab11 to navigate GCP6/Rab11 vesicles to CEP290, enabling intact γ-tubulin ring complex (γTuRC) assembly for ciliogenesis. CRB3 depletion (Crb3 knockout mice) caused severe primary cilium defects in mammary ductal lumen and renal tubule, and mammary epithelial-specific Crb3 KO promoted ductal hyperplasia and tumorigenesis. CRB3-depleted cells are unresponsive to Hh pathway activation, and CRB3 regulates Wnt signaling.","method":"Crb3 knockout and conditional knockout mice (mammary epithelial-specific), Co-IP (CRB3-Rab11, GCP6/Rab11-CEP290), subcellular localization (basal body, Rab11 vesicles), ciliogenesis assays, Hh/Wnt pathway activation assays","journal":"eLife","confidence":"High","confidence_rationale":"Tier 1–2 / Strong — in vivo genetic KO models, Co-IP for molecular interactions, mechanistic reconstitution of γTuRC pathway, multiple orthogonal assays","pmids":["37737843"],"is_preprint":false},{"year":2023,"finding":"In Xenopus laevis MCCs, Crb3.L localizes to cytoplasmic vesicles near ascending centrioles/basal bodies, colocalizing partially with Rab11a. Crb3.L depletion causes defective centriole/basal body migration, reduced apical surface, disorganized apical actin meshwork, and defective ciliogenesis; Rab11a depletion phenocopies this. CRB3 anchors phospho-ERM at the growing apical domain to enable actin-dependent apical membrane expansion.","method":"Morpholino-mediated knockdown (Crb3.L and Rab11a) in Xenopus MCCs, colocalization imaging (Crb3.L/Rab11a), apical surface quantification, actin meshwork analysis, pERM localization","journal":"Journal of cell science","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — morpholino KD with phenotypic readout, colocalization, Rab11a epistasis; single lab, Xenopus model","pmids":["37840525"],"is_preprint":false},{"year":2025,"finding":"CRB3A interacts with Merlin/NF2 via its FERM-binding domain (FBD). CRB3 deficiency in colonoids leads to increased RhoA activity, hypercontractile perijunctional actomyosin, elevated junctional tension (increased vinculin), and defective AJC assembly; NF2 knockdown phenocopies CRB3 loss. ROCK-II or myosin II inhibition rescues junctional architecture in CRB3-null cells.","method":"Conditional Crb3 knockout colonoids, Co-IP (CRB3-NF2 via FBD), RhoA activity assay, ROCK-II/myosin II inhibitor rescue, vinculin localization, NF2 knockdown epistasis","journal":"JCI insight","confidence":"High","confidence_rationale":"Tier 2 / Moderate — reciprocal Co-IP with domain specificity, conditional KO in primary cells, epistasis (NF2 KD phenocopy), pharmacological rescue; single lab but multiple orthogonal methods","pmids":["41122968"],"is_preprint":false},{"year":2007,"finding":"CRB3 overexpression does not interact with presenilin complex components and does not affect γ/ε-secretase activity (Aβ, AICD, or NICD production) in mammalian cells — negative result.","method":"Co-immunoprecipitation, γ-secretase activity assays (Aβ/AICD/NICD measurement), NCT maturation and PS endoproteolysis assays","journal":"Biochemistry","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — negative result established by Co-IP and functional assays; single lab but multiple readouts","pmids":["17988153"],"is_preprint":false}],"current_model":"CRB3 is an apical transmembrane polarity protein that coordinates epithelial and ciliary organization through multiple mechanisms: its C-terminal ERLI (PDZ-binding) domain directly binds Par6 to regulate tight junction formation; its FERM-binding domain interacts with Merlin/NF2 to control perijunctional actomyosin contractility and AJC assembly via RhoA/ROCK signaling; it localizes to the basal body via Rab11-positive endosomes to navigate GCP6/Rab11 vesicles to CEP290 for γTuRC assembly and ciliogenesis; it acts as an upstream activator of the Hippo pathway (recruiting Kibra/FRMD6 → LATS1/2 → YAP inhibition) to enforce contact inhibition; and its mRNA stability is regulated by METTL3-mediated m6A modification read by YTHDF2, placing CRB3 at the intersection of epithelial polarity, actin cytoskeletal dynamics, ciliogenesis, and Hippo/Wnt/Hh tumor suppressive signaling."},"narrative":{"mechanistic_narrative":"CRB3 is an apical transmembrane polarity protein that organizes epithelial junctions, the actin cytoskeleton, and ciliogenesis while serving as an upstream activator of tumor-suppressive Hippo signaling [PMID:14718572, PMID:28079891, PMID:37737843]. Through its C-terminal ERLI (PDZ-binding) motif it directly binds Par6, with apical delivery of the Par6-aPKC complex facilitated by Morg1 and reinforced by Cdc42, to govern tight junction maturation and 3D cyst morphogenesis [PMID:14718572, PMID:23439680]. A distinct FERM-binding domain mediates interaction with Merlin/NF2 to restrain RhoA-driven perijunctional actomyosin contractility and junctional tension, such that CRB3 loss produces hypercontractile, mistensioned junctions rescued by ROCK-II or myosin II inhibition [PMID:41122968]; CRB3 also couples to branched-actin and capping regulators Arp3 and Eps8 and anchors phospho-ERM to support apical actin organization and membrane expansion [PMID:27358069, PMID:37840525]. CRB3 promotes ciliogenesis by trafficking through Rab11-positive endosomes to the basal body, where it routes GCP6/Rab11 vesicles to CEP290 to enable γTuRC assembly; its loss causes primary cilium defects, ductal hyperplasia and tumorigenesis in vivo and abrogates responsiveness to Hedgehog and Wnt signaling [PMID:37737843]. As a Hippo activator, CRB3 recruits Kibra/FRMD6 to engage LATS1/2 and inactivate YAP/TAZ, enforcing contact inhibition; this axis is suppressed transcriptionally by MUC1-C/ZEB1 occupancy of the CRB3 promoter and post-transcriptionally by METTL3-deposited m6A read by YTHDF2 to degrade CRB3 mRNA, and CRB3 downregulation drives EMT, YAP/TAZ–β-catenin activation, and cancer stem cell properties [PMID:28079891, PMID:27658423, PMID:28436991, PMID:35012593]. CRB3 overexpression does not engage the presenilin/γ-secretase complex [PMID:17988153].","teleology":[{"year":2004,"claim":"Established the molecular basis by which CRB3 engages the apical polarity machinery, showing its C-terminal ERLI motif directly binds Par6 and that this interaction tunes tight junction formation.","evidence":"Direct binding assay and ERLI-domain deletion/chimera overexpression with TJ permeability readouts in MDCK cells","pmids":["14718572"],"confidence":"High","gaps":["Did not resolve how the Par6-aPKC complex is targeted apically","No structural detail of the ERLI-Par6 interface"]},{"year":2013,"claim":"Answered how the Par6-aPKC complex reaches CRB3 at the apical membrane, identifying Morg1 as the targeting factor reinforced by Cdc42.","evidence":"Reciprocal Co-IP, Morg1 depletion with forced apical aPKC rescue, monolayer TJ and 3D cyst assays in MDCK cells","pmids":["23439680"],"confidence":"High","gaps":["Does not establish stoichiometry of the Morg1-Par6-CRB3 assembly","Role of Cdc42 nucleotide state not defined"]},{"year":2016,"claim":"Linked CRB3 to direct actin regulation by showing it binds Arp3 and Eps8 to maintain microfilament architecture underpinning the blood-testis barrier.","evidence":"Co-IP, RNAi knockdown with TJ-permeability assay in Sertoli cells, in vivo knockdown with spermatid phenotypes","pmids":["27358069"],"confidence":"Medium","gaps":["Single lab; binding partners by Co-IP without reciprocal/structural validation","Whether CRB3 directly regulates Arp3/Eps8 activity versus localization unresolved"]},{"year":2016,"claim":"Extended CRB3 function beyond epithelia, demonstrating it activates Hippo to inhibit YAP and limit myelin elongation in peripheral nerve.","evidence":"In vivo immunofluorescence localization, Dy2j/2j mouse model, YAP nuclear activity and nerve conduction readouts","pmids":["27435623"],"confidence":"Medium","gaps":["Direct Hippo-component interactions in Schwann cells not mapped","Single lab"]},{"year":2016,"claim":"Identified a transcriptional silencing route for CRB3, with MUC1-C/ZEB1 repressing its promoter to disable Hippo and license YAP/β-catenin–MYC signaling in TNBC.","evidence":"ChIP for promoter occupancy, CRB3 mRNA/protein measurement, LATS1 phosphorylation, YAP localization, YAP/β-catenin Co-IP","pmids":["27658423"],"confidence":"Medium","gaps":["Direct versus indirect ZEB1 binding not fully dissected","Single lab"]},{"year":2017,"claim":"Defined the Hippo-activating mechanism, showing CRB3 recruits Kibra/FRMD6 to drive LATS1/2 activation, YAP inactivation, and contact inhibition with tumor suppression.","evidence":"Co-IP of CRB3 with Kibra/FRMD6, OE/KD with Hippo pathway readouts, proliferation/apoptosis assays, in vivo tumor suppression in mammary epithelial cells","pmids":["28079891"],"confidence":"Medium","gaps":["Whether Kibra/FRMD6 recruitment is direct or scaffold-mediated unclear","Single lab"]},{"year":2017,"claim":"Showed that CRB3 loss is sufficient to drive malignant phenotypes, inducing EMT and cancer stem cell properties through TAZ and β-catenin activation.","evidence":"CRB3 knockdown in MCF-10A, TAZ/β-catenin activation assays, sphere formation, epistatic phenocopy by TAZ/β-catenin activation","pmids":["28436991"],"confidence":"Medium","gaps":["Mechanistic link between CRB3 loss and β-catenin activation not resolved","Single lab"]},{"year":2018,"claim":"Separated CRB3 signaling outputs by domain, showing FERM-binding-domain-dependent, EPB41L4B-mediated proliferation via amphiregulin secretion that is independent of the PDZ-binding domain.","evidence":"FBD vs PDZ-binding domain deletion constructs, AREG secretion and endosome quantification, EPB41L4B knockdown, 3D acini culture","pmids":["30440051"],"confidence":"Medium","gaps":["How EPB41L4B couples CRB3 to AREG secretion mechanistically unclear","Single lab"]},{"year":2022,"claim":"Revealed post-transcriptional control of CRB3, establishing an m6A-CRB3-Hippo axis in which METTL3/YTHDF2 degrade CRB3 mRNA to suppress Hippo activation.","evidence":"MeRIP-qPCR, RNA stability and luciferase assays, YTHDF2-CRB3 mRNA RIP, METTL3/YTHDF2 KD with CRB3 readouts, CRB3-KD reversal epistasis","pmids":["35012593"],"confidence":"Medium","gaps":["Mapped m6A sites and their individual contributions not fully defined","Single lab"]},{"year":2023,"claim":"Uncovered a ciliogenic role, showing CRB3 traffics via Rab11 endosomes to the basal body to route GCP6/Rab11 vesicles to CEP290 for γTuRC assembly, with loss causing cilium defects, hyperplasia, and impaired Hh/Wnt responsiveness.","evidence":"Crb3 global and mammary-conditional knockout mice, Co-IP (CRB3-Rab11, GCP6/Rab11-CEP290), basal body localization, ciliogenesis and Hh/Wnt activation assays","pmids":["37737843"],"confidence":"High","gaps":["Order of CRB3 actions at basal body versus apical membrane not fully resolved","How CRB3 selects Rab11 vesicle cargo unknown"]},{"year":2023,"claim":"Corroborated the ciliary trafficking role in a second system, showing Crb3.L works with Rab11a in Xenopus MCCs to drive basal body migration, apical expansion, and apical actin/pERM organization.","evidence":"Morpholino knockdown of Crb3.L and Rab11a in Xenopus MCCs, colocalization imaging, apical surface and actin meshwork analysis, pERM localization","pmids":["37840525"],"confidence":"Medium","gaps":["Morpholino-based; off-target controls and rescue depth limited","Direct CRB3-pERM interaction not demonstrated"]},{"year":2025,"claim":"Defined how CRB3 controls junctional mechanics, showing FBD-mediated binding to Merlin/NF2 restrains RhoA-driven perijunctional actomyosin contractility and enables proper AJC assembly.","evidence":"Conditional Crb3 KO colonoids, Co-IP (CRB3-NF2 via FBD), RhoA activity assay, NF2-KD epistasis, ROCK-II/myosin II inhibitor rescue, vinculin localization","pmids":["41122968"],"confidence":"High","gaps":["How CRB3-NF2 binding inhibits RhoA mechanistically unresolved","Single lab"]},{"year":null,"claim":"It remains unresolved how CRB3's distinct activities — Par6/junction control, NF2/actomyosin tension, Rab11-dependent ciliogenesis, and Hippo activation — are coordinated spatially and temporally on a single apical protein.","evidence":"No integrative study in the corpus reconstitutes these branches together","pmids":[],"confidence":"Medium","gaps":["No structural model integrating FBD and PDZ-binding outputs","Hierarchy between ciliary and junctional CRB3 pools undefined","In vivo coordination across tissues not established"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0060090","term_label":"molecular adaptor activity","supporting_discovery_ids":[0,1,4,9,11]},{"term_id":"GO:0008092","term_label":"cytoskeletal protein binding","supporting_discovery_ids":[2,10]}],"localization":[{"term_id":"GO:0005886","term_label":"plasma membrane","supporting_discovery_ids":[0,1,10]},{"term_id":"GO:0005815","term_label":"microtubule organizing center","supporting_discovery_ids":[9,10]},{"term_id":"GO:0031410","term_label":"cytoplasmic vesicle","supporting_discovery_ids":[9,10]},{"term_id":"GO:0005929","term_label":"cilium","supporting_discovery_ids":[9,10]}],"pathway":[{"term_id":"R-HSA-162582","term_label":"Signal Transduction","supporting_discovery_ids":[4,5,9]},{"term_id":"R-HSA-1852241","term_label":"Organelle biogenesis and maintenance","supporting_discovery_ids":[9,10]},{"term_id":"R-HSA-8953854","term_label":"Metabolism of RNA","supporting_discovery_ids":[8]},{"term_id":"R-HSA-1266738","term_label":"Developmental Biology","supporting_discovery_ids":[3,9]}],"complexes":[],"partners":["PARD6","NF2","RAB11A","KIBRA","FRMD6","ARP3","EPS8","EPB41L4B"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"Q9BUF7","full_name":"Protein crumbs homolog 3","aliases":[],"length_aa":120,"mass_kda":12.9,"function":"Involved in the establishment of cell polarity in mammalian epithelial cells (PubMed:12771187, PubMed:14718572, PubMed:23439680). Regulates the morphogenesis of tight junctions (PubMed:12771187, PubMed:14718572). Involved in promoting phosphorylation and cytoplasmic retention of transcriptional coactivators YAP1 and WWTR1/TAZ which leads to suppression of TGFB1-dependent transcription of target genes such as CCN2/CTGF, SERPINE1/PAI1, SNAI1/SNAIL1 and SMAD7 (By similarity)","subcellular_location":"Apical cell membrane; Cell junction, tight junction","url":"https://www.uniprot.org/uniprotkb/Q9BUF7/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/CRB3","classification":"Not Classified","n_dependent_lines":17,"n_total_lines":1208,"dependency_fraction":0.014072847682119206},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/CRB3","total_profiled":1310},"omim":[{"mim_id":"616850","title":"WD REPEAT-CONTAINING PROTEIN 83; WDR83","url":"https://www.omim.org/entry/616850"},{"mim_id":"611730","title":"ERYTHROCYTE MEMBRANE PROTEIN BAND 4.1-LIKE 5; EPB41L5","url":"https://www.omim.org/entry/611730"},{"mim_id":"610973","title":"MEMBRANE PROTEIN, PALMITOYLATED 7; MPP7","url":"https://www.omim.org/entry/610973"},{"mim_id":"609737","title":"CRUMBS CELL POLARITY COMPLEX COMPONENT 3; CRB3","url":"https://www.omim.org/entry/609737"},{"mim_id":"607484","title":"PAR6 FAMILY CELL POLARITY REGULATOR ALPHA; PARD6A","url":"https://www.omim.org/entry/607484"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Supported","locations":[{"location":"Cell Junctions","reliability":"Supported"}],"tissue_specificity":"Tissue enhanced","tissue_distribution":"Detected in many","driving_tissues":[{"tissue":"esophagus","ntpm":52.7}],"url":"https://www.proteinatlas.org/search/CRB3"},"hgnc":{"alias_symbol":["MGC17303"],"prev_symbol":[]},"alphafold":{"accession":"Q9BUF7","domains":[{"cath_id":"-","chopping":"5-104","consensus_level":"medium","plddt":69.4099,"start":5,"end":104}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q9BUF7","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q9BUF7-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q9BUF7-F1-predicted_aligned_error_v6.png","plddt_mean":69.44},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=CRB3","jax_strain_url":"https://www.jax.org/strain/search?query=CRB3"},"sequence":{"accession":"Q9BUF7","fasta_url":"https://rest.uniprot.org/uniprotkb/Q9BUF7.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q9BUF7/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q9BUF7"}},"corpus_meta":[{"pmid":"14718572","id":"PMC_14718572","title":"CRB3 binds 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ciliogenesis.","date":"2023","source":"eLife","url":"https://pubmed.ncbi.nlm.nih.gov/37737843","citation_count":5,"is_preprint":false},{"pmid":"31087799","id":"PMC_31087799","title":"Crumbs protein homolog 3 (CRB3) expression is associated with oestrogen and progesterone receptor positivity in breast cancer.","date":"2019","source":"Clinical and experimental pharmacology & physiology","url":"https://pubmed.ncbi.nlm.nih.gov/31087799","citation_count":3,"is_preprint":false},{"pmid":"30440051","id":"PMC_30440051","title":"CRB3 and the FERM protein EPB41L4B regulate proliferation of mammary epithelial cells through the release of amphiregulin.","date":"2018","source":"PloS one","url":"https://pubmed.ncbi.nlm.nih.gov/30440051","citation_count":2,"is_preprint":false},{"pmid":"38353316","id":"PMC_38353316","title":"Intestinal mRNA expression analysis of polarity-related genes identified the discriminatory ability of CRB3 as a diagnostic marker for celiac disease.","date":"2024","source":"Immunity, inflammation and disease","url":"https://pubmed.ncbi.nlm.nih.gov/38353316","citation_count":2,"is_preprint":false},{"pmid":"41122968","id":"PMC_41122968","title":"CRB3 and NF2 orchestrate cytoskeletal dynamics to control epithelial barrier assembly.","date":"2025","source":"JCI insight","url":"https://pubmed.ncbi.nlm.nih.gov/41122968","citation_count":0,"is_preprint":false},{"pmid":"37840525","id":"PMC_37840525","title":"Crb3 is required to organize the apical domain of multiciliated cells.","date":"2023","source":"Journal of cell science","url":"https://pubmed.ncbi.nlm.nih.gov/37840525","citation_count":0,"is_preprint":false},{"pmid":"39868176","id":"PMC_39868176","title":"Crb3 and NF2: A dynamic duo that controls assembly of the apical junctions and barrier function via Rho/ROCK signaling.","date":"2025","source":"bioRxiv : the preprint server for biology","url":"https://pubmed.ncbi.nlm.nih.gov/39868176","citation_count":0,"is_preprint":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":13154,"output_tokens":3878,"usd":0.048816,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":11466,"output_tokens":4388,"usd":0.083515,"stage2_stop_reason":"end_turn"},"total_usd":0.132331,"stage1_batch_id":"msgbatch_01ACAxJQabDsht39JXeWG22d","stage2_batch_id":"msgbatch_01QEU22A9U5sbPTgsMzTmvSf","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2004,\n      \"finding\": \"CRB3 directly binds Par6 via its C-terminal ERLI motif (PDZ-binding domain), and overexpression of CRB3 slows development of functional tight junctions in MDCK cells in a manner dependent on this ERLI domain.\",\n      \"method\": \"Direct binding assay, domain deletion/chimera overexpression in MDCK cells, tight junction permeability assays\",\n      \"journal\": \"Molecular biology of the cell\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1–2 / Moderate — direct interaction demonstrated with binding assay and domain-specific mutagenesis (ERLI motif), functional phenotype confirmed in epithelial cells with chimeric constructs\",\n      \"pmids\": [\"14718572\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"The WD40 protein Morg1 directly binds Par6 and facilitates apical targeting of the Par6-aPKC complex to CRB3 at the apical membrane; this interaction is reinforced by Cdc42. Depletion of Morg1 disrupts tight junction development and cyst formation, rescued by forced apical targeting of aPKC.\",\n      \"method\": \"Co-IP, epistasis (Morg1 depletion + forced apical aPKC targeting), 3D cyst assay, MDCK cells\",\n      \"journal\": \"The Journal of cell biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — reciprocal Co-IP, genetic epistasis rescue experiment, two orthogonal functional assays (monolayer TJ and 3D cyst)\",\n      \"pmids\": [\"23439680\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"CRB3 interacts with actin-regulatory proteins Arp3 (branched actin polymerization) and Eps8 (barbed-end capping/bundling) in Sertoli cells. CRB3 knockdown disrupts actin microfilament organization, truncating and branching actin, which destabilizes TJ- and basal ES-protein complexes at the blood-testis barrier, and impairs spermatid/phagosome transport and spermatid polarity in vivo.\",\n      \"method\": \"Co-IP (binding partners Arp3 and Eps8), RNAi knockdown in Sertoli cells with TJ-permeability barrier assay, in vivo CRB3 KD via jetPEI transfection with histological readouts\",\n      \"journal\": \"Scientific reports\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2–3 / Moderate — Co-IP for binding partners, RNAi with functional TJ assay, and in vivo knockdown with spermatid phenotype; single lab\",\n      \"pmids\": [\"27358069\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"CRB3, localized at the tips of the peripheral myelin sheath, activates the Hippo pathway to inhibit YAP transcriptional activity, thereby limiting myelin elongation. Loss of CRB3-mediated Hippo activation results in decreased nuclear YAP and shorter myelin internodes in dystrophic mice.\",\n      \"method\": \"In vivo localization (immunofluorescence), genetic mouse model (Dy2j/2j), YAP nuclear activity assays, functional nerve conduction measurements\",\n      \"journal\": \"Nature communications\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — in vivo localization linked to functional pathway (Hippo/YAP) with genetic mouse model and physiological readout; single lab\",\n      \"pmids\": [\"27435623\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"CRB3 acts as an upstream activator of the Hippo pathway in mammary epithelial cells by recruiting Kibra and/or FRMD6, leading to activation of LATS1/2 kinases, YAP inactivation, and contact inhibition of proliferation.\",\n      \"method\": \"Co-immunoprecipitation (CRB3 with Kibra/FRMD6), CRB3 overexpression and knockdown with Hippo pathway readouts (LATS phosphorylation, YAP localization), proliferation and apoptosis assays, in vivo tumor suppression\",\n      \"journal\": \"Cell death & disease\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2–3 / Moderate — Co-IP for Kibra/FRMD6 interaction, KD/OE with pathway readouts; single lab\",\n      \"pmids\": [\"28079891\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"MUC1-C associates with ZEB1 on the CRB3 promoter to repress CRB3 transcription in triple-negative breast cancer cells, thereby suppressing CRB3-driven Hippo pathway activation (LATS1/2), leading to YAP dephosphorylation/activation, YAP/β-catenin complex formation, and MYC induction.\",\n      \"method\": \"ChIP (MUC1-C/ZEB1 on CRB3 promoter), CRB3 mRNA/protein measurement upon MUC1-C targeting, LATS1 phosphorylation assay, YAP localization, Co-IP (YAP/β-catenin), MYC expression\",\n      \"journal\": \"Molecular cancer research : MCR\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — ChIP for promoter occupancy, multiple downstream pathway readouts; single lab\",\n      \"pmids\": [\"27658423\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"CRB3 downregulation in MCF-10A cells induces EMT, activates TAZ and β-catenin signaling, and confers cancer stem cell properties; TAZ and β-catenin activation was sufficient to recapitulate the CSC phenotype caused by CRB3 loss.\",\n      \"method\": \"CRB3 knockdown in MCF-10A, TAZ/β-catenin activation assays, sphere formation and CSC marker assays, epistasis (TAZ/β-catenin activation phenocopy)\",\n      \"journal\": \"Oncogenesis\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2–3 / Moderate — KD with multiple functional readouts and pathway activation, epistasis by activation of TAZ/β-catenin; single lab\",\n      \"pmids\": [\"28436991\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"CRB3 overexpression drives proliferation in mammary epithelial cells through increased secretion of amphiregulin (AREG), in a manner dependent on the FERM-binding domain (FBD) but not the PDZ-binding domain of CRB3. EPB41L4B was identified as an essential FBD-dependent mediator of CRB3-driven proliferation and associated changes in endocytic trafficking.\",\n      \"method\": \"CRB3 domain deletion constructs (FBD vs PDZ-binding domain), AREG secretion assay, endosome size/number quantification, EPB41L4B knockdown, 3D acini culture assay\",\n      \"journal\": \"PloS one\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2–3 / Moderate — domain-specific mutagenesis/deletion, downstream mediator knockdown, multiple orthogonal assays; single lab\",\n      \"pmids\": [\"30440051\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"METTL3-mediated m6A methylation of CRB3 mRNA promotes its degradation via YTHDF2 binding. METTL3 knockdown reduces m6A on CRB3 mRNA, increases CRB3 expression, and activates the Hippo pathway (reducing nuclear YAP); these effects are reversed by CRB3 knockdown, placing CRB3 downstream of METTL3/YTHDF2 in an m6A-CRB3-Hippo axis.\",\n      \"method\": \"m6A epitranscriptomic microarray, MeRIP-qPCR, RNA stability assay, luciferase reporter, RNA immunoprecipitation (YTHDF2-CRB3 mRNA), METTL3/YTHDF2 knockdown with CRB3 mRNA/protein readouts, epistasis (CRB3 KD reversal of Hippo activation)\",\n      \"journal\": \"Journal of experimental & clinical cancer research : CR\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — multiple orthogonal RNA-level assays (MeRIP, RIP, luciferase, stability), epistasis experiment; single lab\",\n      \"pmids\": [\"35012593\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"CRB3 localizes to the basal body and is trafficked via Rab11-positive endosomes. CRB3 interacts with Rab11 to navigate GCP6/Rab11 vesicles to CEP290, enabling intact γ-tubulin ring complex (γTuRC) assembly for ciliogenesis. CRB3 depletion (Crb3 knockout mice) caused severe primary cilium defects in mammary ductal lumen and renal tubule, and mammary epithelial-specific Crb3 KO promoted ductal hyperplasia and tumorigenesis. CRB3-depleted cells are unresponsive to Hh pathway activation, and CRB3 regulates Wnt signaling.\",\n      \"method\": \"Crb3 knockout and conditional knockout mice (mammary epithelial-specific), Co-IP (CRB3-Rab11, GCP6/Rab11-CEP290), subcellular localization (basal body, Rab11 vesicles), ciliogenesis assays, Hh/Wnt pathway activation assays\",\n      \"journal\": \"eLife\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1–2 / Strong — in vivo genetic KO models, Co-IP for molecular interactions, mechanistic reconstitution of γTuRC pathway, multiple orthogonal assays\",\n      \"pmids\": [\"37737843\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"In Xenopus laevis MCCs, Crb3.L localizes to cytoplasmic vesicles near ascending centrioles/basal bodies, colocalizing partially with Rab11a. Crb3.L depletion causes defective centriole/basal body migration, reduced apical surface, disorganized apical actin meshwork, and defective ciliogenesis; Rab11a depletion phenocopies this. CRB3 anchors phospho-ERM at the growing apical domain to enable actin-dependent apical membrane expansion.\",\n      \"method\": \"Morpholino-mediated knockdown (Crb3.L and Rab11a) in Xenopus MCCs, colocalization imaging (Crb3.L/Rab11a), apical surface quantification, actin meshwork analysis, pERM localization\",\n      \"journal\": \"Journal of cell science\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — morpholino KD with phenotypic readout, colocalization, Rab11a epistasis; single lab, Xenopus model\",\n      \"pmids\": [\"37840525\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"CRB3A interacts with Merlin/NF2 via its FERM-binding domain (FBD). CRB3 deficiency in colonoids leads to increased RhoA activity, hypercontractile perijunctional actomyosin, elevated junctional tension (increased vinculin), and defective AJC assembly; NF2 knockdown phenocopies CRB3 loss. ROCK-II or myosin II inhibition rescues junctional architecture in CRB3-null cells.\",\n      \"method\": \"Conditional Crb3 knockout colonoids, Co-IP (CRB3-NF2 via FBD), RhoA activity assay, ROCK-II/myosin II inhibitor rescue, vinculin localization, NF2 knockdown epistasis\",\n      \"journal\": \"JCI insight\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — reciprocal Co-IP with domain specificity, conditional KO in primary cells, epistasis (NF2 KD phenocopy), pharmacological rescue; single lab but multiple orthogonal methods\",\n      \"pmids\": [\"41122968\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2007,\n      \"finding\": \"CRB3 overexpression does not interact with presenilin complex components and does not affect γ/ε-secretase activity (Aβ, AICD, or NICD production) in mammalian cells — negative result.\",\n      \"method\": \"Co-immunoprecipitation, γ-secretase activity assays (Aβ/AICD/NICD measurement), NCT maturation and PS endoproteolysis assays\",\n      \"journal\": \"Biochemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — negative result established by Co-IP and functional assays; single lab but multiple readouts\",\n      \"pmids\": [\"17988153\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"CRB3 is an apical transmembrane polarity protein that coordinates epithelial and ciliary organization through multiple mechanisms: its C-terminal ERLI (PDZ-binding) domain directly binds Par6 to regulate tight junction formation; its FERM-binding domain interacts with Merlin/NF2 to control perijunctional actomyosin contractility and AJC assembly via RhoA/ROCK signaling; it localizes to the basal body via Rab11-positive endosomes to navigate GCP6/Rab11 vesicles to CEP290 for γTuRC assembly and ciliogenesis; it acts as an upstream activator of the Hippo pathway (recruiting Kibra/FRMD6 → LATS1/2 → YAP inhibition) to enforce contact inhibition; and its mRNA stability is regulated by METTL3-mediated m6A modification read by YTHDF2, placing CRB3 at the intersection of epithelial polarity, actin cytoskeletal dynamics, ciliogenesis, and Hippo/Wnt/Hh tumor suppressive signaling.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"CRB3 is an apical transmembrane polarity protein that organizes epithelial junctions, the actin cytoskeleton, and ciliogenesis while serving as an upstream activator of tumor-suppressive Hippo signaling [#0, #4, #9]. Through its C-terminal ERLI (PDZ-binding) motif it directly binds Par6, with apical delivery of the Par6-aPKC complex facilitated by Morg1 and reinforced by Cdc42, to govern tight junction maturation and 3D cyst morphogenesis [#0, #1]. A distinct FERM-binding domain mediates interaction with Merlin/NF2 to restrain RhoA-driven perijunctional actomyosin contractility and junctional tension, such that CRB3 loss produces hypercontractile, mistensioned junctions rescued by ROCK-II or myosin II inhibition [#11]; CRB3 also couples to branched-actin and capping regulators Arp3 and Eps8 and anchors phospho-ERM to support apical actin organization and membrane expansion [#2, #10]. CRB3 promotes ciliogenesis by trafficking through Rab11-positive endosomes to the basal body, where it routes GCP6/Rab11 vesicles to CEP290 to enable γTuRC assembly; its loss causes primary cilium defects, ductal hyperplasia and tumorigenesis in vivo and abrogates responsiveness to Hedgehog and Wnt signaling [#9]. As a Hippo activator, CRB3 recruits Kibra/FRMD6 to engage LATS1/2 and inactivate YAP/TAZ, enforcing contact inhibition; this axis is suppressed transcriptionally by MUC1-C/ZEB1 occupancy of the CRB3 promoter and post-transcriptionally by METTL3-deposited m6A read by YTHDF2 to degrade CRB3 mRNA, and CRB3 downregulation drives EMT, YAP/TAZ–β-catenin activation, and cancer stem cell properties [#4, #5, #6, #8]. CRB3 overexpression does not engage the presenilin/γ-secretase complex [#12].\",\n  \"teleology\": [\n    {\n      \"year\": 2004,\n      \"claim\": \"Established the molecular basis by which CRB3 engages the apical polarity machinery, showing its C-terminal ERLI motif directly binds Par6 and that this interaction tunes tight junction formation.\",\n      \"evidence\": \"Direct binding assay and ERLI-domain deletion/chimera overexpression with TJ permeability readouts in MDCK cells\",\n      \"pmids\": [\"14718572\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not resolve how the Par6-aPKC complex is targeted apically\", \"No structural detail of the ERLI-Par6 interface\"]\n    },\n    {\n      \"year\": 2013,\n      \"claim\": \"Answered how the Par6-aPKC complex reaches CRB3 at the apical membrane, identifying Morg1 as the targeting factor reinforced by Cdc42.\",\n      \"evidence\": \"Reciprocal Co-IP, Morg1 depletion with forced apical aPKC rescue, monolayer TJ and 3D cyst assays in MDCK cells\",\n      \"pmids\": [\"23439680\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Does not establish stoichiometry of the Morg1-Par6-CRB3 assembly\", \"Role of Cdc42 nucleotide state not defined\"]\n    },\n    {\n      \"year\": 2016,\n      \"claim\": \"Linked CRB3 to direct actin regulation by showing it binds Arp3 and Eps8 to maintain microfilament architecture underpinning the blood-testis barrier.\",\n      \"evidence\": \"Co-IP, RNAi knockdown with TJ-permeability assay in Sertoli cells, in vivo knockdown with spermatid phenotypes\",\n      \"pmids\": [\"27358069\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Single lab; binding partners by Co-IP without reciprocal/structural validation\", \"Whether CRB3 directly regulates Arp3/Eps8 activity versus localization unresolved\"]\n    },\n    {\n      \"year\": 2016,\n      \"claim\": \"Extended CRB3 function beyond epithelia, demonstrating it activates Hippo to inhibit YAP and limit myelin elongation in peripheral nerve.\",\n      \"evidence\": \"In vivo immunofluorescence localization, Dy2j/2j mouse model, YAP nuclear activity and nerve conduction readouts\",\n      \"pmids\": [\"27435623\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct Hippo-component interactions in Schwann cells not mapped\", \"Single lab\"]\n    },\n    {\n      \"year\": 2016,\n      \"claim\": \"Identified a transcriptional silencing route for CRB3, with MUC1-C/ZEB1 repressing its promoter to disable Hippo and license YAP/β-catenin–MYC signaling in TNBC.\",\n      \"evidence\": \"ChIP for promoter occupancy, CRB3 mRNA/protein measurement, LATS1 phosphorylation, YAP localization, YAP/β-catenin Co-IP\",\n      \"pmids\": [\"27658423\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct versus indirect ZEB1 binding not fully dissected\", \"Single lab\"]\n    },\n    {\n      \"year\": 2017,\n      \"claim\": \"Defined the Hippo-activating mechanism, showing CRB3 recruits Kibra/FRMD6 to drive LATS1/2 activation, YAP inactivation, and contact inhibition with tumor suppression.\",\n      \"evidence\": \"Co-IP of CRB3 with Kibra/FRMD6, OE/KD with Hippo pathway readouts, proliferation/apoptosis assays, in vivo tumor suppression in mammary epithelial cells\",\n      \"pmids\": [\"28079891\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Whether Kibra/FRMD6 recruitment is direct or scaffold-mediated unclear\", \"Single lab\"]\n    },\n    {\n      \"year\": 2017,\n      \"claim\": \"Showed that CRB3 loss is sufficient to drive malignant phenotypes, inducing EMT and cancer stem cell properties through TAZ and β-catenin activation.\",\n      \"evidence\": \"CRB3 knockdown in MCF-10A, TAZ/β-catenin activation assays, sphere formation, epistatic phenocopy by TAZ/β-catenin activation\",\n      \"pmids\": [\"28436991\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Mechanistic link between CRB3 loss and β-catenin activation not resolved\", \"Single lab\"]\n    },\n    {\n      \"year\": 2018,\n      \"claim\": \"Separated CRB3 signaling outputs by domain, showing FERM-binding-domain-dependent, EPB41L4B-mediated proliferation via amphiregulin secretion that is independent of the PDZ-binding domain.\",\n      \"evidence\": \"FBD vs PDZ-binding domain deletion constructs, AREG secretion and endosome quantification, EPB41L4B knockdown, 3D acini culture\",\n      \"pmids\": [\"30440051\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"How EPB41L4B couples CRB3 to AREG secretion mechanistically unclear\", \"Single lab\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Revealed post-transcriptional control of CRB3, establishing an m6A-CRB3-Hippo axis in which METTL3/YTHDF2 degrade CRB3 mRNA to suppress Hippo activation.\",\n      \"evidence\": \"MeRIP-qPCR, RNA stability and luciferase assays, YTHDF2-CRB3 mRNA RIP, METTL3/YTHDF2 KD with CRB3 readouts, CRB3-KD reversal epistasis\",\n      \"pmids\": [\"35012593\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Mapped m6A sites and their individual contributions not fully defined\", \"Single lab\"]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"Uncovered a ciliogenic role, showing CRB3 traffics via Rab11 endosomes to the basal body to route GCP6/Rab11 vesicles to CEP290 for γTuRC assembly, with loss causing cilium defects, hyperplasia, and impaired Hh/Wnt responsiveness.\",\n      \"evidence\": \"Crb3 global and mammary-conditional knockout mice, Co-IP (CRB3-Rab11, GCP6/Rab11-CEP290), basal body localization, ciliogenesis and Hh/Wnt activation assays\",\n      \"pmids\": [\"37737843\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Order of CRB3 actions at basal body versus apical membrane not fully resolved\", \"How CRB3 selects Rab11 vesicle cargo unknown\"]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"Corroborated the ciliary trafficking role in a second system, showing Crb3.L works with Rab11a in Xenopus MCCs to drive basal body migration, apical expansion, and apical actin/pERM organization.\",\n      \"evidence\": \"Morpholino knockdown of Crb3.L and Rab11a in Xenopus MCCs, colocalization imaging, apical surface and actin meshwork analysis, pERM localization\",\n      \"pmids\": [\"37840525\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Morpholino-based; off-target controls and rescue depth limited\", \"Direct CRB3-pERM interaction not demonstrated\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Defined how CRB3 controls junctional mechanics, showing FBD-mediated binding to Merlin/NF2 restrains RhoA-driven perijunctional actomyosin contractility and enables proper AJC assembly.\",\n      \"evidence\": \"Conditional Crb3 KO colonoids, Co-IP (CRB3-NF2 via FBD), RhoA activity assay, NF2-KD epistasis, ROCK-II/myosin II inhibitor rescue, vinculin localization\",\n      \"pmids\": [\"41122968\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"How CRB3-NF2 binding inhibits RhoA mechanistically unresolved\", \"Single lab\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"It remains unresolved how CRB3's distinct activities — Par6/junction control, NF2/actomyosin tension, Rab11-dependent ciliogenesis, and Hippo activation — are coordinated spatially and temporally on a single apical protein.\",\n      \"evidence\": \"No integrative study in the corpus reconstitutes these branches together\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No structural model integrating FBD and PDZ-binding outputs\", \"Hierarchy between ciliary and junctional CRB3 pools undefined\", \"In vivo coordination across tissues not established\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0060090\", \"supporting_discovery_ids\": [0, 1, 4, 9, 11]},\n      {\"term_id\": \"GO:0008092\", \"supporting_discovery_ids\": [2, 10]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005886\", \"supporting_discovery_ids\": [0, 1, 10]},\n      {\"term_id\": \"GO:0005815\", \"supporting_discovery_ids\": [9, 10]},\n      {\"term_id\": \"GO:0031410\", \"supporting_discovery_ids\": [9, 10]},\n      {\"term_id\": \"GO:0005929\", \"supporting_discovery_ids\": [9, 10]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-162582\", \"supporting_discovery_ids\": [4, 5, 9]},\n      {\"term_id\": \"R-HSA-1852241\", \"supporting_discovery_ids\": [9, 10]},\n      {\"term_id\": \"R-HSA-8953854\", \"supporting_discovery_ids\": [8]},\n      {\"term_id\": \"R-HSA-1266738\", \"supporting_discovery_ids\": [3, 9]}\n    ],\n    \"complexes\": [],\n    \"partners\": [\"PARD6\", \"NF2\", \"RAB11A\", \"KIBRA\", \"FRMD6\", \"ARP3\", \"EPS8\", \"EPB41L4B\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":6,"faith_total":6,"faith_pct":100.0}}