{"gene":"LZTS2","run_date":"2026-06-10T02:59:50","timeline":{"discoveries":[{"year":2006,"finding":"LZTS2 directly interacts with β-catenin, represses β-catenin-mediated transactivation, and promotes nuclear export of β-catenin via a functional nuclear export signal (NES) in its C-terminus (amino acids 631–641) that operates through the CRM1/exportin pathway; point mutations in the NES leucine residues abolish nuclear exclusion, and leptomycin B (CRM1 inhibitor) blocks LZTS2 nuclear export and retains β-catenin in the nucleus.","method":"Co-immunoprecipitation, GFP fusion/localization assays, NES point mutagenesis, leptomycin B treatment, β-catenin nuclear level quantification in SW480 cells","journal":"Molecular and cellular biology","confidence":"High","confidence_rationale":"Tier 2 / Strong — multiple orthogonal methods (Co-IP, mutagenesis, chemical inhibition, overexpression) in a single focused study, replicated in zebrafish and other systems","pmids":["17000760"],"is_preprint":false},{"year":2007,"finding":"LZTS2 colocalizes with γ-tubulin, MKLP1, and p80 katanin at centrosomes and midbodies in mitotic cells; RNAi-mediated knockdown of LZTS2 causes mislocalization of p80 katanin and malformation of the central spindle; overexpression of LZTS2 induces binucleation and abortive cytokinesis in a p80 katanin-dependent manner, implicating LZTS2 in cytokinesis regulation through interaction with p80 katanin.","method":"Immunofluorescence co-localization, RNAi knockdown, overexpression, caspase inhibitor rescue (Z-VAD-fmk), v-Fps oncogene transformation assay","journal":"FASEB journal","confidence":"High","confidence_rationale":"Tier 2 / Strong — multiple orthogonal methods (RNAi, OE, rescue, localization) in one study, replicated in subsequent in vitro katanin-severing assay paper","pmids":["17351128"],"is_preprint":false},{"year":2008,"finding":"The C-terminal domain of LZTS2/LAPSER1 directly inhibits katanin-mediated microtubule severing in vitro; LZTS2 localizes preferentially to mother centrioles independently of microtubules; LZTS2 inhibits central spindle formation by abrogating microtubule transportation; interphase LZTS2 expression increases acetylated (stable) microtubules and prevents cell motility; LZTS2 knockdown increases cell migration, which is rescued by ninein (a microtubule-release inhibitor).","method":"In vitro microtubule severing assay, live-cell microtubule tracing, immunofluorescence, RNAi knockdown, overexpression, ninein rescue experiment","journal":"Human molecular genetics","confidence":"High","confidence_rationale":"Tier 1 / Moderate — in vitro reconstitution assay for katanin inhibition plus multiple cellular experiments in one study","pmids":["18490357"],"is_preprint":false},{"year":2009,"finding":"LZTS2/LAPSER1 localizes to the postsynaptic density and directly binds ProSAP2/Shank3 and the synaptic Rap-GAP protein SPAR1; upon NMDA receptor activation, LZTS2 and β-catenin co-migrate from the postsynaptic density to the nucleus and induce transcription of β-catenin target genes Tcfe2a and c-Myc; LZTS2 regulates the nuclear export and cytoplasmic redistribution of β-catenin in a synaptic-activity-dependent manner.","method":"Co-immunoprecipitation, immunofluorescence co-localization, NMDA receptor stimulation, transcriptional reporter assays, western blot","journal":"The Journal of biological chemistry","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — reciprocal Co-IP and functional reporter assays, single lab","pmids":["19703901"],"is_preprint":false},{"year":2011,"finding":"In Xenopus laevis, LZTS2/LAPSER1 interacts with all three ProSAP/Shank family members (Shank1, ProSAP1/Shank2, ProSAP2/Shank3) and co-localizes with ProSAP/Shank in a cell-based assay.","method":"Co-immunoprecipitation in Xenopus embryos, cell-based co-localization assay","journal":"Developmental dynamics","confidence":"Low","confidence_rationale":"Tier 3 / Weak — single Co-IP in embryo lysate, single lab, limited mechanistic follow-up","pmids":["21445960"],"is_preprint":false},{"year":2011,"finding":"In zebrafish, Lzts2 physically interacts with β-catenin-1 and β-catenin-2 and transports them out of the nucleus; loss of Lzts2 (morpholino) enhances convergence-extension movements and dorsalizes embryos, while ectopic Lzts2 delays convergence-extension and ventralizes embryos, placing Lzts2 downstream of Wnt/β-catenin signaling and upstream of BMP signaling in dorsoventral patterning.","method":"Morpholino knockdown, mRNA overexpression, co-immunoprecipitation, subcellular localization assays, epistasis analysis in zebrafish embryos","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 2 / Moderate — genetic epistasis combined with Co-IP and localization in a vertebrate in vivo model, multiple orthogonal approaches","pmids":["22057270"],"is_preprint":false},{"year":2011,"finding":"In Lzts2 knockout mice, β-catenin subcellular localization is altered in null fibroblasts, and Wnt-induced β-catenin-mediated transcriptional activity is increased, demonstrating a direct role for Lzts2 in the Wnt/β-catenin pathway in vivo; homozygous Lzts2 null embryos show severe kidney/urinary tract developmental defects including altered ureteric bud outgrowth.","method":"Lzts2 knockout mouse model, fibroblast isolation, β-catenin localization assay, Wnt-stimulated transcriptional reporter assay","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 2 / Strong — clean KO mouse model with defined cellular phenotype and mechanistic readout, consistent with multiple other studies","pmids":["21949185"],"is_preprint":false},{"year":2007,"finding":"In human adipose tissue-derived mesenchymal stem cells, NF-κB activity regulates LZTS2 expression; knockdown of LZTS2 by RNAi increases nuclear translocation of β-catenin and increases NF-κB activity, accompanied by increased β-TrCP1 expression and decreased IκB levels, demonstrating that LZTS2 mediates cross-regulation between the β-catenin/Tcf and NF-κB signaling pathways.","method":"RNAi knockdown, nuclear fractionation/localization assay, NF-κB and Tcf reporter assays, western blot in hASCs and hBMSCs","journal":"Biochimica et biophysica acta","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — clean RNAi with multiple pathway readouts, single lab","pmids":["17950943"],"is_preprint":false},{"year":2018,"finding":"LZTS2 interacts with the PI3K regulatory subunit p85 and competes with the PI3K catalytic subunit p110 for p85 binding, thereby inhibiting PI3K/AKT signaling activation; this interaction is required for LZTS2-mediated suppression of tumorigenesis and radioresistance in nasopharyngeal carcinoma.","method":"Unbiased proteomics (co-IP/MS), competitive binding assay (p85/p110 competition), functional rescue assays in cell lines and xenografts","journal":"Cancer letters","confidence":"High","confidence_rationale":"Tier 2 / Moderate — unbiased proteomics identification plus functional competition assay, multiple cellular and in vivo experiments, single lab","pmids":["29409973"],"is_preprint":false},{"year":2021,"finding":"LZTS2 is a bona fide substrate of the E3 ubiquitin ligase β-TrCP and the protein kinase CK1δ, which phosphorylate and ubiquitinate LZTS2 to drive its proteasomal degradation; this β-TrCP/CK1δ-mediated degradation of LZTS2 activates PI3K/AKT signaling and promotes hepatocellular carcinoma progression and metastasis.","method":"Co-immunoprecipitation, ubiquitination assays, kinase assays, in vitro and in vivo functional assays, rescue experiments","journal":"Oncogene","confidence":"High","confidence_rationale":"Tier 2 / Moderate — biochemical substrate identification with ubiquitination and kinase assays, multiple functional validations in vitro and in vivo, single lab","pmids":["33420362"],"is_preprint":false},{"year":2024,"finding":"CCDC137 binds LZTS2 and recruits the E3 ubiquitin ligase β-TrCP to promote K48-linked poly-ubiquitination of LZTS2 at lysine 467 in the nucleus, leading to LZTS2 degradation, AKT phosphorylation, and β-catenin pathway activation; the 1–75 domain of CCDC137 mediates formation of the CCDC137-LZTS2-β-TrCP complex.","method":"Co-immunoprecipitation, ubiquitination assay (K48-linkage specific), domain mapping, peptide disruption assays, HCC organoids and PDX models","journal":"Cell death and differentiation","confidence":"High","confidence_rationale":"Tier 2 / Moderate — defined ubiquitination site (K467), linkage type, and complex components with multiple orthogonal methods and in vivo validation","pmids":["38918619"],"is_preprint":false},{"year":2024,"finding":"PLK1 binds LZTS2 and phosphorylates it at Ser451; this phosphorylation disrupts the interaction between LZTS2 and β-catenin, leading to nuclear accumulation of β-catenin and activation of the Wnt pathway without affecting LZTS2 protein stability.","method":"Co-immunoprecipitation, phosphorylation site mutagenesis (Ser451), in vitro kinase assay (implied), β-catenin nuclear localization assay, proliferation/migration functional assays","journal":"Cellular signalling","confidence":"Medium","confidence_rationale":"Tier 2 / Weak — phosphorylation site identified by mutagenesis with functional readout, single lab, limited kinase assay detail in abstract","pmids":["38740232"],"is_preprint":false},{"year":2025,"finding":"The E3 ligase SPOP promotes ubiquitination-mediated degradation of LZTS2; the deubiquitinase HAUSP counteracts SPOP and stabilizes LZTS2; SPOP and HAUSP compete for binding to the same region of LZTS2, bidirectionally regulating LZTS2 stability and consequently Wnt pathway activity in colorectal cancer cells.","method":"Co-immunoprecipitation, ubiquitination assay, deubiquitination assay, competitive binding assay, cell proliferation and metastasis functional assays","journal":"Cell death & disease","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — bidirectional ubiquitination/deubiquitination assays with competition binding, single lab","pmids":["41436424"],"is_preprint":false},{"year":2025,"finding":"LZTS2 enriches at the midbody/intercellular bridges and at apical adhering junctions (including tight and tricellular junctions) in epithelial cells; α-catenin M-domain conformational opening (mechanosensitive unfurling) promotes junctional sequestration of LZTS2 away from the cytosol; LZTS2 knockdown increases cytokinesis failure and binucleation, establishing LZTS2 as a mechanosensitive effector of α-catenin required for cytokinetic fidelity.","method":"α-catenin KO/reconstitution (MDCK cells), biotin-ligase proximity labeling, immunofluorescence, LZTS2 knockdown, binucleation quantification, α-catenin M-domain mutagenesis","journal":"The Journal of cell biology","confidence":"High","confidence_rationale":"Tier 2 / Strong — multiple orthogonal methods (proximity labeling, KO reconstitution, mutagenesis, KD phenotype), published in peer-reviewed journal","pmids":["39786338"],"is_preprint":false},{"year":2025,"finding":"LZTS2 knockdown increases microtubule nucleation at the centrosome; LZTS2 negatively regulates centrosomal levels of CEP135; depletion of LZTS2 partially rescues the impaired centrosomal microtubule nucleation caused by CEP135 knockdown, placing LZTS2 upstream of CEP135 in centrosomal microtubule nucleation control.","method":"RNAi knockdown, fluorescence microscopy, electron microscopy, centrosome microtubule nucleation assay, genetic epistasis (double knockdown rescue)","journal":"Cytoskeleton (Hoboken, N.J.)","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — genetic epistasis and direct centrosomal nucleation measurement, single lab, single study","pmids":["40521914"],"is_preprint":false},{"year":2025,"finding":"SH3RF2 (an E3 ubiquitin ligase) interacts with LZTS2 via its RING domain and promotes ubiquitination-mediated degradation of LZTS2, resulting in nuclear translocation of β-catenin; overexpression of LZTS2 attenuates SH3RF2-induced β-catenin nuclear translocation.","method":"Proteomic interaction analysis, co-immunoprecipitation, ubiquitination assay, overexpression rescue, in vivo tumor assay","journal":"Biology direct","confidence":"Medium","confidence_rationale":"Tier 2 / Weak — interaction and ubiquitination identified, rescue experiment confirms pathway placement, single lab","pmids":["40676695"],"is_preprint":false},{"year":2026,"finding":"In Xenopus laevis, Lzts2 knockdown disrupts craniofacial morphogenesis and reduces expression of neural crest markers sox9 and pax3; sub-phenotypic reductions of Lzts2 and Dyrk1a synergize to produce craniofacial defects, while partial reduction of Lzts2 attenuates phenotypes caused by Dyrk1a overexpression, establishing a functional genetic interaction between LZTS2 and DYRK1A during embryonic craniofacial development.","method":"Morpholino knockdown, mRNA overexpression, genetic epistasis (sub-phenotypic co-knockdown and rescue), in situ hybridization for sox9/pax3","journal":"bioRxiv","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — genetic epistasis with multiple allele combinations in a vertebrate model, preprint not yet peer-reviewed","pmids":["41959346"],"is_preprint":true}],"current_model":"LZTS2 is a multifunctional tumor suppressor that (1) binds β-catenin and drives its nuclear export via a CRM1-dependent NES, thereby repressing Wnt/β-catenin transcription; (2) inhibits PI3K/AKT signaling by competing with the catalytic p110 subunit for binding to the regulatory p85 subunit; (3) suppresses centrosomal microtubule severing by inhibiting p80 katanin and negatively regulates CEP135 to control microtubule nucleation; (4) acts as a mechanosensitive effector of α-catenin at the midbody and adherens junctions to ensure cytokinetic fidelity; and (5) is itself regulated by multiple ubiquitin ligases (β-TrCP, SPOP, CCDC137-recruited β-TrCP, SH3RF2) and kinases (CK1δ, PLK1), whose activities control LZTS2 stability and phosphorylation-dependent interaction with β-catenin."},"narrative":{"mechanistic_narrative":"LZTS2 is a tumor suppressor that restrains Wnt/β-catenin signaling by directly binding β-catenin and exporting it from the nucleus through a C-terminal CRM1-dependent nuclear export signal, thereby repressing β-catenin-mediated transactivation [PMID:17000760]. This regulatory function is conserved and operates in vivo: loss of Lzts2 in zebrafish and knockout mice alters β-catenin localization and amplifies Wnt-induced transcription, with developmental consequences for dorsoventral patterning and kidney/urinary tract morphogenesis [PMID:22057270, PMID:21949185]. In parallel, LZTS2 inhibits PI3K/AKT signaling by binding the regulatory subunit p85 and competing with the catalytic p110 subunit, an interaction required for its suppression of tumorigenesis and radioresistance [PMID:29409973]. Beyond signaling, LZTS2 governs microtubule and cytokinetic control: it localizes to centrosomes and midbodies, directly inhibits p80 katanin-mediated microtubule severing, negatively regulates centrosomal CEP135 and microtubule nucleation, and acts as a mechanosensitive effector of α-catenin at adherens junctions to ensure cytokinetic fidelity, with its loss causing binucleation and cytokinesis failure [PMID:17351128, PMID:18490357, PMID:39786338, PMID:40521914]. LZTS2 abundance and activity are tightly controlled post-translationally by multiple E3 ligases and kinases—β-TrCP/CK1δ, CCDC137-recruited β-TrCP, SPOP (opposed by the deubiquitinase HAUSP), and SH3RF2 drive its degradation, while PLK1 phosphorylation at Ser451 disrupts its β-catenin interaction without affecting stability—thereby derepressing both Wnt and PI3K/AKT signaling in cancer [PMID:33420362, PMID:38918619, PMID:38740232, PMID:41436424, PMID:40676695].","teleology":[{"year":2006,"claim":"Established the core molecular mechanism by which LZTS2 antagonizes Wnt signaling, answering how it controls β-catenin: through direct binding and active CRM1-dependent nuclear export.","evidence":"Co-IP, GFP-localization, NES point mutagenesis and leptomycin B treatment in SW480 cells","pmids":["17000760"],"confidence":"High","gaps":["Did not define the β-catenin-binding domain of LZTS2","Did not address whether export is regulated by upstream signals"]},{"year":2007,"claim":"Extended LZTS2 beyond transcriptional control into mitosis, showing it regulates cytokinesis through interaction with p80 katanin at centrosomes and midbodies.","evidence":"Immunofluorescence co-localization, RNAi, overexpression, and caspase-inhibitor rescue","pmids":["17351128"],"confidence":"High","gaps":["Did not establish whether katanin regulation is direct","Binucleation mechanism not resolved at this stage"]},{"year":2007,"claim":"Connected LZTS2 to a second signaling axis, demonstrating it mediates cross-regulation between β-catenin/Tcf and NF-κB pathways.","evidence":"RNAi knockdown with nuclear fractionation and NF-κB/Tcf reporter assays in human mesenchymal stem cells","pmids":["17950943"],"confidence":"Medium","gaps":["Direct versus indirect NF-κB regulation not distinguished","β-TrCP1 induction mechanism not mechanistically dissected"]},{"year":2008,"claim":"Provided the biochemical basis for LZTS2's cytoskeletal role, showing direct inhibition of katanin severing and stabilization of microtubules that restrains cell motility.","evidence":"In vitro microtubule severing reconstitution, live-cell microtubule tracing, RNAi, and ninein rescue","pmids":["18490357"],"confidence":"High","gaps":["Link between microtubule stabilization and tumor suppression not directly tested","Domain mediating katanin inhibition only broadly localized to C-terminus"]},{"year":2009,"claim":"Revealed a neuronal, activity-dependent dimension of LZTS2 function, coupling synaptic NMDA receptor activation to β-catenin nuclear shuttling and target gene transcription.","evidence":"Reciprocal Co-IP, NMDA stimulation, and transcriptional reporter assays at the postsynaptic density","pmids":["19703901"],"confidence":"Medium","gaps":["Single lab; physiological relevance of nuclear co-migration in neurons not independently confirmed","Role of Shank3/SPAR1 binding in regulating β-catenin export unresolved"]},{"year":2011,"claim":"Validated LZTS2's Wnt-regulatory function in vivo across vertebrates, placing it downstream of Wnt and upstream of BMP in patterning and confirming its requirement for normal development.","evidence":"Zebrafish morpholino/mRNA epistasis with Co-IP, and Lzts2 knockout mouse with β-catenin localization and reporter assays","pmids":["22057270","21949185"],"confidence":"High","gaps":["Tissue-specific contributions of LZTS2 in mammalian development not dissected","Cytoskeletal versus transcriptional contributions to phenotypes not separated"]},{"year":2018,"claim":"Identified a distinct tumor-suppressive mechanism, showing LZTS2 inhibits PI3K/AKT signaling by competing with p110 for the p85 regulatory subunit.","evidence":"Unbiased co-IP/MS, competitive binding assay, and rescue experiments in nasopharyngeal carcinoma cells and xenografts","pmids":["29409973"],"confidence":"High","gaps":["Structural basis of p85 competition not defined","Crosstalk between LZTS2's Wnt and PI3K functions unexplored"]},{"year":2021,"claim":"Defined how LZTS2 levels are controlled, identifying it as a CK1δ-phosphorylated, β-TrCP-ubiquitinated substrate whose degradation activates PI3K/AKT and drives HCC progression.","evidence":"Co-IP, ubiquitination and kinase assays with in vitro and in vivo functional validation","pmids":["33420362"],"confidence":"High","gaps":["Phospho-degron sequence not pinpointed","Whether the same degradation controls Wnt output not tested here"]},{"year":2024,"claim":"Refined the degradation mechanism by identifying an adaptor and a specific ubiquitination site, showing CCDC137 recruits β-TrCP for nuclear K48 poly-ubiquitination of LZTS2 at K467.","evidence":"K48-linkage ubiquitination assays, domain mapping, peptide disruption, HCC organoids and PDX models","pmids":["38918619"],"confidence":"High","gaps":["Signals controlling CCDC137-LZTS2 engagement unknown","Relationship to CK1δ phosphorylation not integrated"]},{"year":2024,"claim":"Distinguished phospho-regulation of LZTS2 activity from stability, showing PLK1 phosphorylation at Ser451 disrupts β-catenin binding to activate Wnt without degrading LZTS2.","evidence":"Co-IP, Ser451 mutagenesis, and β-catenin nuclear localization and functional assays","pmids":["38740232"],"confidence":"Medium","gaps":["Direct kinase assay detail limited","Cell-cycle context of PLK1-LZTS2 regulation not defined"]},{"year":2025,"claim":"Expanded the regulatory network with additional opposing enzymes, showing SPOP and SH3RF2 degrade LZTS2 while HAUSP stabilizes it, collectively tuning Wnt activity in cancer.","evidence":"Ubiquitination/deubiquitination and competitive binding assays in colorectal cancer cells; proteomic interaction and ubiquitination with in vivo tumor assays for SH3RF2","pmids":["41436424","40676695"],"confidence":"Medium","gaps":["Whether these ligases act in distinct tissues or compete is unclear","SPOP/HAUSP binding region overlap mapped only coarsely"]},{"year":2025,"claim":"Unified LZTS2's mitotic roles by placing it within junctional mechanosensing and centrosomal nucleation control, establishing it as an α-catenin effector required for cytokinetic fidelity and an upstream regulator of CEP135.","evidence":"α-catenin KO/reconstitution and M-domain mutagenesis with proximity labeling in MDCK cells; RNAi epistasis and centrosomal nucleation assays","pmids":["39786338","40521914"],"confidence":"High","gaps":["How junctional sequestration of LZTS2 integrates with its katanin/CEP135 functions unresolved","Mechanism linking α-catenin tension to LZTS2 release not biochemically defined"]},{"year":2026,"claim":"Identified a developmental genetic interaction, showing LZTS2 and DYRK1A cooperate during craniofacial and neural crest morphogenesis.","evidence":"Xenopus morpholino/mRNA epistasis with in situ hybridization for sox9/pax3 (preprint)","pmids":["41959346"],"confidence":"Medium","gaps":["Preprint not yet peer-reviewed","Molecular basis of the LZTS2-DYRK1A interaction undefined","Whether interaction occurs through Wnt or a distinct pathway unknown"]},{"year":null,"claim":"How LZTS2's multiple activities—β-catenin export, PI3K inhibition, microtubule/cytokinesis control, and junctional mechanosensing—are coordinated within a single cell, and which dominate in specific tissues, remains unresolved.","evidence":"","pmids":[],"confidence":"Medium","gaps":["No integrated structural model of LZTS2 domains and their respective binding partners","Spatial/temporal partitioning of LZTS2 between nucleus, centrosome, midbody, and junctions not defined","Whether degradation by the various E3 ligases is tissue- or context-specific is unknown"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0098772","term_label":"molecular function regulator activity","supporting_discovery_ids":[2,8,14]},{"term_id":"GO:0008092","term_label":"cytoskeletal protein binding","supporting_discovery_ids":[1,2,14]},{"term_id":"GO:0140313","term_label":"molecular sequestering activity","supporting_discovery_ids":[0,5]},{"term_id":"GO:0140110","term_label":"transcription regulator activity","supporting_discovery_ids":[0,6]}],"localization":[{"term_id":"GO:0005815","term_label":"microtubule organizing center","supporting_discovery_ids":[1,2,14]},{"term_id":"GO:0005634","term_label":"nucleus","supporting_discovery_ids":[0,6,10]},{"term_id":"GO:0005829","term_label":"cytosol","supporting_discovery_ids":[0,13]},{"term_id":"GO:0005886","term_label":"plasma membrane","supporting_discovery_ids":[13]},{"term_id":"GO:0005856","term_label":"cytoskeleton","supporting_discovery_ids":[2]}],"pathway":[{"term_id":"R-HSA-162582","term_label":"Signal Transduction","supporting_discovery_ids":[0,8,5]},{"term_id":"R-HSA-1640170","term_label":"Cell Cycle","supporting_discovery_ids":[1,13,14]},{"term_id":"R-HSA-1266738","term_label":"Developmental Biology","supporting_discovery_ids":[5,6]},{"term_id":"R-HSA-392499","term_label":"Metabolism of proteins","supporting_discovery_ids":[9,10,12,15]},{"term_id":"R-HSA-1643685","term_label":"Disease","supporting_discovery_ids":[8,9,10,12]}],"complexes":["CCDC137-LZTS2-β-TrCP complex","adherens junction"],"partners":["CTNNB1","KATNB1","PIK3R1","CCDC137","BTRC","SPOP","USP7","SHANK3"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"Q9BRK4","full_name":"Leucine zipper putative tumor suppressor 2","aliases":["Protein LAPSER1"],"length_aa":669,"mass_kda":72.8,"function":"Negative regulator of katanin-mediated microtubule severing and release from the centrosome. Required for central spindle formation and the completion of cytokinesis. May negatively regulate axonal outgrowth by preventing the formation of microtubule bundles that are necessary for transport within the elongating axon. Negative regulator of the Wnt signaling pathway. Represses beta-catenin-mediated transcriptional activation by promoting the nuclear exclusion of beta-catenin","subcellular_location":"Cytoplasm; Cytoplasm, cytoskeleton, microtubule organizing center, centrosome","url":"https://www.uniprot.org/uniprotkb/Q9BRK4/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/LZTS2","classification":"Not Classified","n_dependent_lines":2,"n_total_lines":1208,"dependency_fraction":0.0016556291390728477},"opencell":{"profiled":true,"resolved_as":"","ensg_id":"ENSG00000107816","cell_line_id":"CID000948","localizations":[{"compartment":"cell_contact","grade":3},{"compartment":"centrosome","grade":3},{"compartment":"membrane","grade":3},{"compartment":"cytoplasmic","grade":1}],"interactors":[{"gene":"RANGAP1","stoichiometry":10.0},{"gene":"TPR","stoichiometry":4.0},{"gene":"BMS1","stoichiometry":0.2},{"gene":"LZTS1","stoichiometry":0.2}],"url":"https://opencell.sf.czbiohub.org/target/CID000948","total_profiled":1310},"omim":[{"mim_id":"610454","title":"LEUCINE ZIPPER, PUTATIVE TUMOR SUPPRESSOR 2; LZTS2","url":"https://www.omim.org/entry/610454"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Approved","locations":[{"location":"Plasma membrane","reliability":"Approved"},{"location":"Cytosol","reliability":"Approved"}],"tissue_specificity":"Low tissue specificity","tissue_distribution":"Detected in all","driving_tissues":[],"url":"https://www.proteinatlas.org/search/LZTS2"},"hgnc":{"alias_symbol":["KIAA1813","LAPSER1"],"prev_symbol":[]},"alphafold":{"accession":"Q9BRK4","domains":[{"cath_id":"1.20.5","chopping":"574-629","consensus_level":"medium","plddt":95.0811,"start":574,"end":629}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q9BRK4","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q9BRK4-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q9BRK4-F1-predicted_aligned_error_v6.png","plddt_mean":65.31},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=LZTS2","jax_strain_url":"https://www.jax.org/strain/search?query=LZTS2"},"sequence":{"accession":"Q9BRK4","fasta_url":"https://rest.uniprot.org/uniprotkb/Q9BRK4.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q9BRK4/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q9BRK4"}},"corpus_meta":[{"pmid":"17000760","id":"PMC_17000760","title":"LZTS2 is a novel beta-catenin-interacting protein and regulates the nuclear export of beta-catenin.","date":"2006","source":"Molecular and cellular biology","url":"https://pubmed.ncbi.nlm.nih.gov/17000760","citation_count":70,"is_preprint":false},{"pmid":"29409973","id":"PMC_29409973","title":"LZTS2 inhibits PI3K/AKT activation and radioresistance in nasopharyngeal carcinoma by interacting with p85.","date":"2018","source":"Cancer letters","url":"https://pubmed.ncbi.nlm.nih.gov/29409973","citation_count":52,"is_preprint":false},{"pmid":"19703901","id":"PMC_19703901","title":"Synaptic cross-talk between N-methyl-D-aspartate receptors and LAPSER1-beta-catenin at excitatory synapses.","date":"2009","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/19703901","citation_count":47,"is_preprint":false},{"pmid":"11709705","id":"PMC_11709705","title":"LAPSER1: a novel candidate tumor suppressor gene from 10q24.3.","date":"2001","source":"Oncogene","url":"https://pubmed.ncbi.nlm.nih.gov/11709705","citation_count":40,"is_preprint":false},{"pmid":"17351128","id":"PMC_17351128","title":"LAPSER1 is a putative cytokinetic tumor suppressor that shows the same centrosome and midbody subcellular localization pattern as p80 katanin.","date":"2007","source":"FASEB journal : official publication of the Federation of American Societies for Experimental Biology","url":"https://pubmed.ncbi.nlm.nih.gov/17351128","citation_count":39,"is_preprint":false},{"pmid":"18490357","id":"PMC_18490357","title":"LAPSER1/LZTS2: a pluripotent tumor suppressor linked to the inhibition of katanin-mediated microtubule severing.","date":"2008","source":"Human molecular genetics","url":"https://pubmed.ncbi.nlm.nih.gov/18490357","citation_count":30,"is_preprint":false},{"pmid":"33420362","id":"PMC_33420362","title":"β-Trcp and CK1δ-mediated degradation of LZTS2 activates PI3K/AKT signaling to drive tumorigenesis and metastasis in hepatocellular carcinoma.","date":"2021","source":"Oncogene","url":"https://pubmed.ncbi.nlm.nih.gov/33420362","citation_count":26,"is_preprint":false},{"pmid":"23275340","id":"PMC_23275340","title":"Deletion of leucine zipper tumor suppressor 2 (Lzts2) increases susceptibility to tumor development.","date":"2012","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/23275340","citation_count":25,"is_preprint":false},{"pmid":"17950943","id":"PMC_17950943","title":"Crossregulation of beta-catenin/Tcf pathway by NF-kappaB is mediated by lzts2 in human adipose tissue-derived mesenchymal stem cells.","date":"2007","source":"Biochimica et biophysica acta","url":"https://pubmed.ncbi.nlm.nih.gov/17950943","citation_count":23,"is_preprint":false},{"pmid":"22057270","id":"PMC_22057270","title":"Lzts2 regulates embryonic cell movements and dorsoventral patterning through interaction with and export of nuclear β-catenin in zebrafish.","date":"2011","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/22057270","citation_count":21,"is_preprint":false},{"pmid":"36750557","id":"PMC_36750557","title":"RRP15 deficiency induces ribosome stress to inhibit colorectal cancer proliferation and metastasis via LZTS2-mediated β-catenin suppression.","date":"2023","source":"Cell death & disease","url":"https://pubmed.ncbi.nlm.nih.gov/36750557","citation_count":18,"is_preprint":false},{"pmid":"21949185","id":"PMC_21949185","title":"The leucine zipper putative tumor suppressor 2 protein LZTS2 regulates kidney development.","date":"2011","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/21949185","citation_count":18,"is_preprint":false},{"pmid":"28323888","id":"PMC_28323888","title":"LZTS2 and PTEN collaboratively regulate ß-catenin in prostatic tumorigenesis.","date":"2017","source":"PloS one","url":"https://pubmed.ncbi.nlm.nih.gov/28323888","citation_count":17,"is_preprint":false},{"pmid":"21445960","id":"PMC_21445960","title":"The spatio-temporal expression of ProSAP/shank family members and their interaction partner LAPSER1 during Xenopus laevis development.","date":"2011","source":"Developmental dynamics : an official publication of the American Association of Anatomists","url":"https://pubmed.ncbi.nlm.nih.gov/21445960","citation_count":14,"is_preprint":false},{"pmid":"38918619","id":"PMC_38918619","title":"Disrupting CCDC137-mediated LZTS2 and β-TrCP interaction in the nucleus inhibits hepatocellular carcinoma development via β-catenin and AKT.","date":"2024","source":"Cell death and differentiation","url":"https://pubmed.ncbi.nlm.nih.gov/38918619","citation_count":10,"is_preprint":false},{"pmid":"38740232","id":"PMC_38740232","title":"Phosphorylation of LZTS2 by PLK1 activates the Wnt pathway.","date":"2024","source":"Cellular signalling","url":"https://pubmed.ncbi.nlm.nih.gov/38740232","citation_count":8,"is_preprint":false},{"pmid":"35179718","id":"PMC_35179718","title":"Long non-coding RNA linc00921 suppresses tumorigenesis and epithelial-to-mesenchymal transition of triple-negative breast cancer via targeting miR-9-5p/LZTS2 axis.","date":"2022","source":"Human cell","url":"https://pubmed.ncbi.nlm.nih.gov/35179718","citation_count":7,"is_preprint":false},{"pmid":"39786338","id":"PMC_39786338","title":"α-Catenin force-sensitive binding and sequestration of LZTS2 leads to cytokinesis failure.","date":"2025","source":"The Journal of cell biology","url":"https://pubmed.ncbi.nlm.nih.gov/39786338","citation_count":4,"is_preprint":false},{"pmid":"37419372","id":"PMC_37419372","title":"EBV-encoded miRNAs BHRF1-1 and BART2-5p aggravate post- transplant lymphoproliferative disorder via LZTS2-PI3K-AKT axis.","date":"2023","source":"Biochemical pharmacology","url":"https://pubmed.ncbi.nlm.nih.gov/37419372","citation_count":2,"is_preprint":false},{"pmid":"41436424","id":"PMC_41436424","title":"SPOP and HAUSP bidirectionally regulate LZTS2 ubiquitination to modulate the Wnt pathway.","date":"2025","source":"Cell death & disease","url":"https://pubmed.ncbi.nlm.nih.gov/41436424","citation_count":0,"is_preprint":false},{"pmid":"40676695","id":"PMC_40676695","title":"The role of SH3RF2 in lung squamous cell carcinoma and M2 polarization: insights into LZTS2 ubiquitination.","date":"2025","source":"Biology direct","url":"https://pubmed.ncbi.nlm.nih.gov/40676695","citation_count":0,"is_preprint":false},{"pmid":"40521914","id":"PMC_40521914","title":"LZTS2 Negatively Regulates Centrosomal CEP135 Levels and Microtubule Nucleation.","date":"2025","source":"Cytoskeleton (Hoboken, N.J.)","url":"https://pubmed.ncbi.nlm.nih.gov/40521914","citation_count":0,"is_preprint":false},{"pmid":"41959346","id":"PMC_41959346","title":"LZTS2 Emerges as a Regulator of Craniofacial Development and Modulator of DYRK1A.","date":"2026","source":"bioRxiv : the preprint server for biology","url":"https://pubmed.ncbi.nlm.nih.gov/41959346","citation_count":0,"is_preprint":false},{"pmid":"37662204","id":"PMC_37662204","title":"α-catenin mechanosensitivity as a route to cytokinesis failure through sequestration of LZTS2.","date":"2023","source":"bioRxiv : the preprint server for biology","url":"https://pubmed.ncbi.nlm.nih.gov/37662204","citation_count":0,"is_preprint":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":13813,"output_tokens":4799,"usd":0.056712,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":12830,"output_tokens":4736,"usd":0.091275,"stage2_stop_reason":"end_turn"},"total_usd":0.147987,"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\": 2006,\n      \"finding\": \"LZTS2 directly interacts with β-catenin, represses β-catenin-mediated transactivation, and promotes nuclear export of β-catenin via a functional nuclear export signal (NES) in its C-terminus (amino acids 631–641) that operates through the CRM1/exportin pathway; point mutations in the NES leucine residues abolish nuclear exclusion, and leptomycin B (CRM1 inhibitor) blocks LZTS2 nuclear export and retains β-catenin in the nucleus.\",\n      \"method\": \"Co-immunoprecipitation, GFP fusion/localization assays, NES point mutagenesis, leptomycin B treatment, β-catenin nuclear level quantification in SW480 cells\",\n      \"journal\": \"Molecular and cellular biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — multiple orthogonal methods (Co-IP, mutagenesis, chemical inhibition, overexpression) in a single focused study, replicated in zebrafish and other systems\",\n      \"pmids\": [\"17000760\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2007,\n      \"finding\": \"LZTS2 colocalizes with γ-tubulin, MKLP1, and p80 katanin at centrosomes and midbodies in mitotic cells; RNAi-mediated knockdown of LZTS2 causes mislocalization of p80 katanin and malformation of the central spindle; overexpression of LZTS2 induces binucleation and abortive cytokinesis in a p80 katanin-dependent manner, implicating LZTS2 in cytokinesis regulation through interaction with p80 katanin.\",\n      \"method\": \"Immunofluorescence co-localization, RNAi knockdown, overexpression, caspase inhibitor rescue (Z-VAD-fmk), v-Fps oncogene transformation assay\",\n      \"journal\": \"FASEB journal\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — multiple orthogonal methods (RNAi, OE, rescue, localization) in one study, replicated in subsequent in vitro katanin-severing assay paper\",\n      \"pmids\": [\"17351128\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2008,\n      \"finding\": \"The C-terminal domain of LZTS2/LAPSER1 directly inhibits katanin-mediated microtubule severing in vitro; LZTS2 localizes preferentially to mother centrioles independently of microtubules; LZTS2 inhibits central spindle formation by abrogating microtubule transportation; interphase LZTS2 expression increases acetylated (stable) microtubules and prevents cell motility; LZTS2 knockdown increases cell migration, which is rescued by ninein (a microtubule-release inhibitor).\",\n      \"method\": \"In vitro microtubule severing assay, live-cell microtubule tracing, immunofluorescence, RNAi knockdown, overexpression, ninein rescue experiment\",\n      \"journal\": \"Human molecular genetics\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — in vitro reconstitution assay for katanin inhibition plus multiple cellular experiments in one study\",\n      \"pmids\": [\"18490357\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2009,\n      \"finding\": \"LZTS2/LAPSER1 localizes to the postsynaptic density and directly binds ProSAP2/Shank3 and the synaptic Rap-GAP protein SPAR1; upon NMDA receptor activation, LZTS2 and β-catenin co-migrate from the postsynaptic density to the nucleus and induce transcription of β-catenin target genes Tcfe2a and c-Myc; LZTS2 regulates the nuclear export and cytoplasmic redistribution of β-catenin in a synaptic-activity-dependent manner.\",\n      \"method\": \"Co-immunoprecipitation, immunofluorescence co-localization, NMDA receptor stimulation, transcriptional reporter assays, western blot\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — reciprocal Co-IP and functional reporter assays, single lab\",\n      \"pmids\": [\"19703901\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2011,\n      \"finding\": \"In Xenopus laevis, LZTS2/LAPSER1 interacts with all three ProSAP/Shank family members (Shank1, ProSAP1/Shank2, ProSAP2/Shank3) and co-localizes with ProSAP/Shank in a cell-based assay.\",\n      \"method\": \"Co-immunoprecipitation in Xenopus embryos, cell-based co-localization assay\",\n      \"journal\": \"Developmental dynamics\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — single Co-IP in embryo lysate, single lab, limited mechanistic follow-up\",\n      \"pmids\": [\"21445960\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2011,\n      \"finding\": \"In zebrafish, Lzts2 physically interacts with β-catenin-1 and β-catenin-2 and transports them out of the nucleus; loss of Lzts2 (morpholino) enhances convergence-extension movements and dorsalizes embryos, while ectopic Lzts2 delays convergence-extension and ventralizes embryos, placing Lzts2 downstream of Wnt/β-catenin signaling and upstream of BMP signaling in dorsoventral patterning.\",\n      \"method\": \"Morpholino knockdown, mRNA overexpression, co-immunoprecipitation, subcellular localization assays, epistasis analysis in zebrafish embryos\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — genetic epistasis combined with Co-IP and localization in a vertebrate in vivo model, multiple orthogonal approaches\",\n      \"pmids\": [\"22057270\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2011,\n      \"finding\": \"In Lzts2 knockout mice, β-catenin subcellular localization is altered in null fibroblasts, and Wnt-induced β-catenin-mediated transcriptional activity is increased, demonstrating a direct role for Lzts2 in the Wnt/β-catenin pathway in vivo; homozygous Lzts2 null embryos show severe kidney/urinary tract developmental defects including altered ureteric bud outgrowth.\",\n      \"method\": \"Lzts2 knockout mouse model, fibroblast isolation, β-catenin localization assay, Wnt-stimulated transcriptional reporter assay\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — clean KO mouse model with defined cellular phenotype and mechanistic readout, consistent with multiple other studies\",\n      \"pmids\": [\"21949185\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2007,\n      \"finding\": \"In human adipose tissue-derived mesenchymal stem cells, NF-κB activity regulates LZTS2 expression; knockdown of LZTS2 by RNAi increases nuclear translocation of β-catenin and increases NF-κB activity, accompanied by increased β-TrCP1 expression and decreased IκB levels, demonstrating that LZTS2 mediates cross-regulation between the β-catenin/Tcf and NF-κB signaling pathways.\",\n      \"method\": \"RNAi knockdown, nuclear fractionation/localization assay, NF-κB and Tcf reporter assays, western blot in hASCs and hBMSCs\",\n      \"journal\": \"Biochimica et biophysica acta\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — clean RNAi with multiple pathway readouts, single lab\",\n      \"pmids\": [\"17950943\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"LZTS2 interacts with the PI3K regulatory subunit p85 and competes with the PI3K catalytic subunit p110 for p85 binding, thereby inhibiting PI3K/AKT signaling activation; this interaction is required for LZTS2-mediated suppression of tumorigenesis and radioresistance in nasopharyngeal carcinoma.\",\n      \"method\": \"Unbiased proteomics (co-IP/MS), competitive binding assay (p85/p110 competition), functional rescue assays in cell lines and xenografts\",\n      \"journal\": \"Cancer letters\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — unbiased proteomics identification plus functional competition assay, multiple cellular and in vivo experiments, single lab\",\n      \"pmids\": [\"29409973\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"LZTS2 is a bona fide substrate of the E3 ubiquitin ligase β-TrCP and the protein kinase CK1δ, which phosphorylate and ubiquitinate LZTS2 to drive its proteasomal degradation; this β-TrCP/CK1δ-mediated degradation of LZTS2 activates PI3K/AKT signaling and promotes hepatocellular carcinoma progression and metastasis.\",\n      \"method\": \"Co-immunoprecipitation, ubiquitination assays, kinase assays, in vitro and in vivo functional assays, rescue experiments\",\n      \"journal\": \"Oncogene\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — biochemical substrate identification with ubiquitination and kinase assays, multiple functional validations in vitro and in vivo, single lab\",\n      \"pmids\": [\"33420362\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"CCDC137 binds LZTS2 and recruits the E3 ubiquitin ligase β-TrCP to promote K48-linked poly-ubiquitination of LZTS2 at lysine 467 in the nucleus, leading to LZTS2 degradation, AKT phosphorylation, and β-catenin pathway activation; the 1–75 domain of CCDC137 mediates formation of the CCDC137-LZTS2-β-TrCP complex.\",\n      \"method\": \"Co-immunoprecipitation, ubiquitination assay (K48-linkage specific), domain mapping, peptide disruption assays, HCC organoids and PDX models\",\n      \"journal\": \"Cell death and differentiation\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — defined ubiquitination site (K467), linkage type, and complex components with multiple orthogonal methods and in vivo validation\",\n      \"pmids\": [\"38918619\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"PLK1 binds LZTS2 and phosphorylates it at Ser451; this phosphorylation disrupts the interaction between LZTS2 and β-catenin, leading to nuclear accumulation of β-catenin and activation of the Wnt pathway without affecting LZTS2 protein stability.\",\n      \"method\": \"Co-immunoprecipitation, phosphorylation site mutagenesis (Ser451), in vitro kinase assay (implied), β-catenin nuclear localization assay, proliferation/migration functional assays\",\n      \"journal\": \"Cellular signalling\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Weak — phosphorylation site identified by mutagenesis with functional readout, single lab, limited kinase assay detail in abstract\",\n      \"pmids\": [\"38740232\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"The E3 ligase SPOP promotes ubiquitination-mediated degradation of LZTS2; the deubiquitinase HAUSP counteracts SPOP and stabilizes LZTS2; SPOP and HAUSP compete for binding to the same region of LZTS2, bidirectionally regulating LZTS2 stability and consequently Wnt pathway activity in colorectal cancer cells.\",\n      \"method\": \"Co-immunoprecipitation, ubiquitination assay, deubiquitination assay, competitive binding assay, cell proliferation and metastasis functional assays\",\n      \"journal\": \"Cell death & disease\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — bidirectional ubiquitination/deubiquitination assays with competition binding, single lab\",\n      \"pmids\": [\"41436424\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"LZTS2 enriches at the midbody/intercellular bridges and at apical adhering junctions (including tight and tricellular junctions) in epithelial cells; α-catenin M-domain conformational opening (mechanosensitive unfurling) promotes junctional sequestration of LZTS2 away from the cytosol; LZTS2 knockdown increases cytokinesis failure and binucleation, establishing LZTS2 as a mechanosensitive effector of α-catenin required for cytokinetic fidelity.\",\n      \"method\": \"α-catenin KO/reconstitution (MDCK cells), biotin-ligase proximity labeling, immunofluorescence, LZTS2 knockdown, binucleation quantification, α-catenin M-domain mutagenesis\",\n      \"journal\": \"The Journal of cell biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — multiple orthogonal methods (proximity labeling, KO reconstitution, mutagenesis, KD phenotype), published in peer-reviewed journal\",\n      \"pmids\": [\"39786338\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"LZTS2 knockdown increases microtubule nucleation at the centrosome; LZTS2 negatively regulates centrosomal levels of CEP135; depletion of LZTS2 partially rescues the impaired centrosomal microtubule nucleation caused by CEP135 knockdown, placing LZTS2 upstream of CEP135 in centrosomal microtubule nucleation control.\",\n      \"method\": \"RNAi knockdown, fluorescence microscopy, electron microscopy, centrosome microtubule nucleation assay, genetic epistasis (double knockdown rescue)\",\n      \"journal\": \"Cytoskeleton (Hoboken, N.J.)\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — genetic epistasis and direct centrosomal nucleation measurement, single lab, single study\",\n      \"pmids\": [\"40521914\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"SH3RF2 (an E3 ubiquitin ligase) interacts with LZTS2 via its RING domain and promotes ubiquitination-mediated degradation of LZTS2, resulting in nuclear translocation of β-catenin; overexpression of LZTS2 attenuates SH3RF2-induced β-catenin nuclear translocation.\",\n      \"method\": \"Proteomic interaction analysis, co-immunoprecipitation, ubiquitination assay, overexpression rescue, in vivo tumor assay\",\n      \"journal\": \"Biology direct\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Weak — interaction and ubiquitination identified, rescue experiment confirms pathway placement, single lab\",\n      \"pmids\": [\"40676695\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2026,\n      \"finding\": \"In Xenopus laevis, Lzts2 knockdown disrupts craniofacial morphogenesis and reduces expression of neural crest markers sox9 and pax3; sub-phenotypic reductions of Lzts2 and Dyrk1a synergize to produce craniofacial defects, while partial reduction of Lzts2 attenuates phenotypes caused by Dyrk1a overexpression, establishing a functional genetic interaction between LZTS2 and DYRK1A during embryonic craniofacial development.\",\n      \"method\": \"Morpholino knockdown, mRNA overexpression, genetic epistasis (sub-phenotypic co-knockdown and rescue), in situ hybridization for sox9/pax3\",\n      \"journal\": \"bioRxiv\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — genetic epistasis with multiple allele combinations in a vertebrate model, preprint not yet peer-reviewed\",\n      \"pmids\": [\"41959346\"],\n      \"is_preprint\": true\n    }\n  ],\n  \"current_model\": \"LZTS2 is a multifunctional tumor suppressor that (1) binds β-catenin and drives its nuclear export via a CRM1-dependent NES, thereby repressing Wnt/β-catenin transcription; (2) inhibits PI3K/AKT signaling by competing with the catalytic p110 subunit for binding to the regulatory p85 subunit; (3) suppresses centrosomal microtubule severing by inhibiting p80 katanin and negatively regulates CEP135 to control microtubule nucleation; (4) acts as a mechanosensitive effector of α-catenin at the midbody and adherens junctions to ensure cytokinetic fidelity; and (5) is itself regulated by multiple ubiquitin ligases (β-TrCP, SPOP, CCDC137-recruited β-TrCP, SH3RF2) and kinases (CK1δ, PLK1), whose activities control LZTS2 stability and phosphorylation-dependent interaction with β-catenin.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"LZTS2 is a tumor suppressor that restrains Wnt/\\u03b2-catenin signaling by directly binding \\u03b2-catenin and exporting it from the nucleus through a C-terminal CRM1-dependent nuclear export signal, thereby repressing \\u03b2-catenin-mediated transactivation [#0]. This regulatory function is conserved and operates in vivo: loss of Lzts2 in zebrafish and knockout mice alters \\u03b2-catenin localization and amplifies Wnt-induced transcription, with developmental consequences for dorsoventral patterning and kidney/urinary tract morphogenesis [#5, #6]. In parallel, LZTS2 inhibits PI3K/AKT signaling by binding the regulatory subunit p85 and competing with the catalytic p110 subunit, an interaction required for its suppression of tumorigenesis and radioresistance [#8]. Beyond signaling, LZTS2 governs microtubule and cytokinetic control: it localizes to centrosomes and midbodies, directly inhibits p80 katanin-mediated microtubule severing, negatively regulates centrosomal CEP135 and microtubule nucleation, and acts as a mechanosensitive effector of \\u03b1-catenin at adherens junctions to ensure cytokinetic fidelity, with its loss causing binucleation and cytokinesis failure [#1, #2, #13, #14]. LZTS2 abundance and activity are tightly controlled post-translationally by multiple E3 ligases and kinases\\u2014\\u03b2-TrCP/CK1\\u03b4, CCDC137-recruited \\u03b2-TrCP, SPOP (opposed by the deubiquitinase HAUSP), and SH3RF2 drive its degradation, while PLK1 phosphorylation at Ser451 disrupts its \\u03b2-catenin interaction without affecting stability\\u2014thereby derepressing both Wnt and PI3K/AKT signaling in cancer [#9, #10, #11, #12, #15].\",\n  \"teleology\": [\n    {\n      \"year\": 2006,\n      \"claim\": \"Established the core molecular mechanism by which LZTS2 antagonizes Wnt signaling, answering how it controls \\u03b2-catenin: through direct binding and active CRM1-dependent nuclear export.\",\n      \"evidence\": \"Co-IP, GFP-localization, NES point mutagenesis and leptomycin B treatment in SW480 cells\",\n      \"pmids\": [\"17000760\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not define the \\u03b2-catenin-binding domain of LZTS2\", \"Did not address whether export is regulated by upstream signals\"]\n    },\n    {\n      \"year\": 2007,\n      \"claim\": \"Extended LZTS2 beyond transcriptional control into mitosis, showing it regulates cytokinesis through interaction with p80 katanin at centrosomes and midbodies.\",\n      \"evidence\": \"Immunofluorescence co-localization, RNAi, overexpression, and caspase-inhibitor rescue\",\n      \"pmids\": [\"17351128\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not establish whether katanin regulation is direct\", \"Binucleation mechanism not resolved at this stage\"]\n    },\n    {\n      \"year\": 2007,\n      \"claim\": \"Connected LZTS2 to a second signaling axis, demonstrating it mediates cross-regulation between \\u03b2-catenin/Tcf and NF-\\u03baB pathways.\",\n      \"evidence\": \"RNAi knockdown with nuclear fractionation and NF-\\u03baB/Tcf reporter assays in human mesenchymal stem cells\",\n      \"pmids\": [\"17950943\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct versus indirect NF-\\u03baB regulation not distinguished\", \"\\u03b2-TrCP1 induction mechanism not mechanistically dissected\"]\n    },\n    {\n      \"year\": 2008,\n      \"claim\": \"Provided the biochemical basis for LZTS2's cytoskeletal role, showing direct inhibition of katanin severing and stabilization of microtubules that restrains cell motility.\",\n      \"evidence\": \"In vitro microtubule severing reconstitution, live-cell microtubule tracing, RNAi, and ninein rescue\",\n      \"pmids\": [\"18490357\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Link between microtubule stabilization and tumor suppression not directly tested\", \"Domain mediating katanin inhibition only broadly localized to C-terminus\"]\n    },\n    {\n      \"year\": 2009,\n      \"claim\": \"Revealed a neuronal, activity-dependent dimension of LZTS2 function, coupling synaptic NMDA receptor activation to \\u03b2-catenin nuclear shuttling and target gene transcription.\",\n      \"evidence\": \"Reciprocal Co-IP, NMDA stimulation, and transcriptional reporter assays at the postsynaptic density\",\n      \"pmids\": [\"19703901\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Single lab; physiological relevance of nuclear co-migration in neurons not independently confirmed\", \"Role of Shank3/SPAR1 binding in regulating \\u03b2-catenin export unresolved\"]\n    },\n    {\n      \"year\": 2011,\n      \"claim\": \"Validated LZTS2's Wnt-regulatory function in vivo across vertebrates, placing it downstream of Wnt and upstream of BMP in patterning and confirming its requirement for normal development.\",\n      \"evidence\": \"Zebrafish morpholino/mRNA epistasis with Co-IP, and Lzts2 knockout mouse with \\u03b2-catenin localization and reporter assays\",\n      \"pmids\": [\"22057270\", \"21949185\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Tissue-specific contributions of LZTS2 in mammalian development not dissected\", \"Cytoskeletal versus transcriptional contributions to phenotypes not separated\"]\n    },\n    {\n      \"year\": 2018,\n      \"claim\": \"Identified a distinct tumor-suppressive mechanism, showing LZTS2 inhibits PI3K/AKT signaling by competing with p110 for the p85 regulatory subunit.\",\n      \"evidence\": \"Unbiased co-IP/MS, competitive binding assay, and rescue experiments in nasopharyngeal carcinoma cells and xenografts\",\n      \"pmids\": [\"29409973\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Structural basis of p85 competition not defined\", \"Crosstalk between LZTS2's Wnt and PI3K functions unexplored\"]\n    },\n    {\n      \"year\": 2021,\n      \"claim\": \"Defined how LZTS2 levels are controlled, identifying it as a CK1\\u03b4-phosphorylated, \\u03b2-TrCP-ubiquitinated substrate whose degradation activates PI3K/AKT and drives HCC progression.\",\n      \"evidence\": \"Co-IP, ubiquitination and kinase assays with in vitro and in vivo functional validation\",\n      \"pmids\": [\"33420362\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Phospho-degron sequence not pinpointed\", \"Whether the same degradation controls Wnt output not tested here\"]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Refined the degradation mechanism by identifying an adaptor and a specific ubiquitination site, showing CCDC137 recruits \\u03b2-TrCP for nuclear K48 poly-ubiquitination of LZTS2 at K467.\",\n      \"evidence\": \"K48-linkage ubiquitination assays, domain mapping, peptide disruption, HCC organoids and PDX models\",\n      \"pmids\": [\"38918619\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Signals controlling CCDC137-LZTS2 engagement unknown\", \"Relationship to CK1\\u03b4 phosphorylation not integrated\"]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Distinguished phospho-regulation of LZTS2 activity from stability, showing PLK1 phosphorylation at Ser451 disrupts \\u03b2-catenin binding to activate Wnt without degrading LZTS2.\",\n      \"evidence\": \"Co-IP, Ser451 mutagenesis, and \\u03b2-catenin nuclear localization and functional assays\",\n      \"pmids\": [\"38740232\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct kinase assay detail limited\", \"Cell-cycle context of PLK1-LZTS2 regulation not defined\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Expanded the regulatory network with additional opposing enzymes, showing SPOP and SH3RF2 degrade LZTS2 while HAUSP stabilizes it, collectively tuning Wnt activity in cancer.\",\n      \"evidence\": \"Ubiquitination/deubiquitination and competitive binding assays in colorectal cancer cells; proteomic interaction and ubiquitination with in vivo tumor assays for SH3RF2\",\n      \"pmids\": [\"41436424\", \"40676695\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Whether these ligases act in distinct tissues or compete is unclear\", \"SPOP/HAUSP binding region overlap mapped only coarsely\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Unified LZTS2's mitotic roles by placing it within junctional mechanosensing and centrosomal nucleation control, establishing it as an \\u03b1-catenin effector required for cytokinetic fidelity and an upstream regulator of CEP135.\",\n      \"evidence\": \"\\u03b1-catenin KO/reconstitution and M-domain mutagenesis with proximity labeling in MDCK cells; RNAi epistasis and centrosomal nucleation assays\",\n      \"pmids\": [\"39786338\", \"40521914\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"How junctional sequestration of LZTS2 integrates with its katanin/CEP135 functions unresolved\", \"Mechanism linking \\u03b1-catenin tension to LZTS2 release not biochemically defined\"]\n    },\n    {\n      \"year\": 2026,\n      \"claim\": \"Identified a developmental genetic interaction, showing LZTS2 and DYRK1A cooperate during craniofacial and neural crest morphogenesis.\",\n      \"evidence\": \"Xenopus morpholino/mRNA epistasis with in situ hybridization for sox9/pax3 (preprint)\",\n      \"pmids\": [\"41959346\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Preprint not yet peer-reviewed\", \"Molecular basis of the LZTS2-DYRK1A interaction undefined\", \"Whether interaction occurs through Wnt or a distinct pathway unknown\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How LZTS2's multiple activities\\u2014\\u03b2-catenin export, PI3K inhibition, microtubule/cytokinesis control, and junctional mechanosensing\\u2014are coordinated within a single cell, and which dominate in specific tissues, remains unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No integrated structural model of LZTS2 domains and their respective binding partners\", \"Spatial/temporal partitioning of LZTS2 between nucleus, centrosome, midbody, and junctions not defined\", \"Whether degradation by the various E3 ligases is tissue- or context-specific is unknown\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0098772\", \"supporting_discovery_ids\": [2, 8, 14]},\n      {\"term_id\": \"GO:0008092\", \"supporting_discovery_ids\": [1, 2, 14]},\n      {\"term_id\": \"GO:0140313\", \"supporting_discovery_ids\": [0, 5]},\n      {\"term_id\": \"GO:0140110\", \"supporting_discovery_ids\": [0, 6]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005815\", \"supporting_discovery_ids\": [1, 2, 14]},\n      {\"term_id\": \"GO:0005634\", \"supporting_discovery_ids\": [0, 6, 10]},\n      {\"term_id\": \"GO:0005829\", \"supporting_discovery_ids\": [0, 13]},\n      {\"term_id\": \"GO:0005886\", \"supporting_discovery_ids\": [13]},\n      {\"term_id\": \"GO:0005856\", \"supporting_discovery_ids\": [2]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-162582\", \"supporting_discovery_ids\": [0, 8, 5]},\n      {\"term_id\": \"R-HSA-1640170\", \"supporting_discovery_ids\": [1, 13, 14]},\n      {\"term_id\": \"R-HSA-1266738\", \"supporting_discovery_ids\": [5, 6]},\n      {\"term_id\": \"R-HSA-392499\", \"supporting_discovery_ids\": [9, 10, 12, 15]},\n      {\"term_id\": \"R-HSA-1643685\", \"supporting_discovery_ids\": [8, 9, 10, 12]}\n    ],\n    \"complexes\": [\n      \"CCDC137-LZTS2-\\u03b2-TrCP complex\",\n      \"adherens junction\"\n    ],\n    \"partners\": [\n      \"CTNNB1\",\n      \"KATNB1\",\n      \"PIK3R1\",\n      \"CCDC137\",\n      \"BTRC\",\n      \"SPOP\",\n      \"USP7\",\n      \"SHANK3\"\n    ],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":5,"faith_total":5,"faith_pct":100.0}}