{"gene":"CLASP2","run_date":"2026-06-09T22:57:18","timeline":{"discoveries":[{"year":2005,"finding":"CLASP1 and CLASP2 bind directly to EB1 via their middle domain, and CLASP2 associates with the cell cortex through its C-terminal domain in an MT-independent manner. Both EB1-binding and cortex-binding domains are required for MT stabilization. CLASPs stabilize MTs by promoting pauses and restricting growth/shortening episodes to the cell periphery.","method":"RNA interference in HeLa cells, direct binding assays, live-cell fluorescence imaging, domain deletion analysis","journal":"The Journal of cell biology","confidence":"High","confidence_rationale":"Tier 2 / Strong — reciprocal binding assays, RNAi phenotype, domain mapping with multiple orthogonal methods, replicated across labs","pmids":["15631994"],"is_preprint":false},{"year":2006,"finding":"CLASP2 is required for formation of a stable, polarized microtubule array at the leading edge of migrating fibroblasts and for persistent directional motility. ACF7 acts upstream of CLASP2 by regulating its cortical localization. CLASP2 is immobilized in a bimodal manner near cell edges to stabilize MTs.","method":"Mouse embryonic fibroblast (MEF) wound-healing assay with CLASP2 knockout, GFP-CLASP2 fluorescence imaging (FRAP), RNAi knockdown of ACF7 in HeLa cells","journal":"Current biology : CB","confidence":"High","confidence_rationale":"Tier 2 / Strong — knockout MEFs with defined phenotype, epistasis placing ACF7 upstream, live imaging, replicated across methods","pmids":["17113391"],"is_preprint":false},{"year":2006,"finding":"CLASP2 localizes to kinetochores, centrosomes, and the spindle throughout mitosis with fast microtubule-independent turnover. Loss of CLASP2 in primary fibroblasts causes spindle and chromosome segregation defects, slower chromosome movement during anaphase A and B, and severe chromosomal instability, which can be partially rescued by ectopic CLASP1 or CLASP2 expression.","method":"Clasp2 knockout mouse fibroblasts, ectopic rescue expression, live-cell imaging, FRAP","journal":"Molecular biology of the cell","confidence":"High","confidence_rationale":"Tier 2 / Strong — genetic knockout with rescue, multiple mitotic phenotypes quantified, FRAP for turnover, replicated","pmids":["16914514"],"is_preprint":false},{"year":2007,"finding":"CLASP2α co-localizes with stress fibers and co-immunoprecipitates with actin. Both the microtubule-binding domain and the N-terminal TOG domain of CLASP2α possess actin-binding activity. FRET experiments confirm proximity between YFP-CLASP2α and CFP-actin, establishing CLASPs as actin/microtubule crosslinkers.","method":"Co-immunoprecipitation, deletion mapping, FRET (YFP/CFP), retrograde flow imaging in Xenopus fibroblasts and neurons","journal":"Cell motility and the cytoskeleton","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — co-IP, FRET, domain mapping, single lab with multiple orthogonal methods","pmids":["17342765"],"is_preprint":false},{"year":2009,"finding":"GSK-3β directly phosphorylates CLASP2 at Ser533 and Ser537, causing dissociation of CLASP2 from IQGAP1, EB1, and microtubules. IQGAP1 was identified as a novel CLASP2-binding protein. Expression of active GSK-3β abolishes CLASP2 distribution on microtubules at leading edges, but a nonphosphorylatable CLASP2 mutant resists this effect.","method":"In vitro phosphorylation assay, co-immunoprecipitation, site-directed mutagenesis, confocal imaging in migrating fibroblasts","journal":"Journal of cell science","confidence":"High","confidence_rationale":"Tier 1-2 / Strong — direct in vitro phosphorylation, mutagenesis (non-phosphorylatable mutant), co-IP, loss-of-function phenotype with multiple orthogonal methods","pmids":["19638411"],"is_preprint":false},{"year":2012,"finding":"During mitosis, CLASP2 is phosphorylated by Cdk1 at S1234, which primes it for Plk1 association and enhances Plk1 recruitment to kinetochores. Plk1 then phosphorylates CLASP2 C-terminal sites, stabilizing kinetochore-MT attachments required for chromosome alignment and spindle bipolarity, and enabling timely SAC satisfaction.","method":"Phospho-site mutagenesis, kinase assays, live-cell imaging, dominant-negative and phosphomimetic constructs","journal":"The Journal of cell biology","confidence":"High","confidence_rationale":"Tier 1-2 / Strong — in vitro kinase assays, mutagenesis of phospho-sites, rescue experiments, multiple functional readouts","pmids":["23045552"],"is_preprint":false},{"year":2012,"finding":"Multisite GSK3 phosphorylation of CLASP2 near its two SXIP EB1-binding motifs disrupts arginine-glutamate salt bridge (electrostatic 'molecular Velcro') interactions required for EB1 binding. Priming phosphorylation by CDKs is required before GSK3 can act; this multisite phosphorylation completely abolishes CLASP2 microtubule plus-end tracking in mitosis.","method":"In vitro binding assays, molecular dynamics simulations, 31P NMR spectroscopy, phosphomimetic mutagenesis, live-cell tracking","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1 / Strong — in vitro reconstitution, NMR, MD simulations, mutagenesis, and live-cell validation, multiple orthogonal methods in one study","pmids":["22467876"],"is_preprint":false},{"year":2012,"finding":"Agrin activates PI3K and inactivates GSK3β locally, leading to CLASP2-mediated capture of dynamic microtubule plus-ends at acetylcholine receptor (AChR) clusters at the neuromuscular junction. Loss of CLASP2 reduces microtubule plus-end density at the synaptic membrane, AChR density, cluster size, and subsynaptic gene expression programs.","method":"RNAi knockdown of CLASP2 in myotubes, pharmacological PI3K/GSK3β manipulation, live and fixed imaging","journal":"The Journal of cell biology","confidence":"High","confidence_rationale":"Tier 2 / Strong — RNAi with defined cellular phenotypes, pharmacological pathway manipulation, multiple readouts linking pathway to CLASP2 function","pmids":["22851317"],"is_preprint":false},{"year":2012,"finding":"CLASP2 knockdown in primary mouse neurons decreases axon and dendritic length, while overexpression causes multiple axon formation, enhanced dendritic branching, Golgi condensation, and increased excitatory synapse number and synaptic transmission, identifying CLASP2 as a regulator of neuronal polarity and synapse formation.","method":"shRNA knockdown and overexpression in primary mouse neurons, confocal imaging, electrophysiology (miniature events), immunostaining","journal":"The Journal of neuroscience","confidence":"High","confidence_rationale":"Tier 2 / Strong — bidirectional manipulation (KD and OE) with defined morphological and electrophysiological phenotypes, multiple readouts","pmids":["23035100"],"is_preprint":false},{"year":2012,"finding":"CLASP2 undergoes insulin-stimulated phosphorylation and co-localizes with GLUT4 at the plasma membrane in areas of cortical actin remodeling. CLASP2 siRNA knockdown in L6 myotubes impairs insulin-stimulated GLUT4 localization to the plasma membrane, and CLASP2 knockdown in 3T3-L1 adipocytes inhibits insulin-stimulated glucose transport.","method":"Mass spectrometry, phosphoantibody immunoprecipitation, confocal imaging, siRNA knockdown, glucose transport assay","journal":"The Journal of biological chemistry","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — siRNA KD with functional glucose transport readout and imaging, single lab, multiple cell types","pmids":["22992739"],"is_preprint":false},{"year":2013,"finding":"CLASP2 directly interacts with p120-catenin and localizes to adherens junctions in primary basal keratinocytes. Reduction in p120 or CLASP2 levels decreases localization of the other protein to cell-cell contacts, alters junction dynamics/stability, and reduces MT density and dynamics at intercellular junctions.","method":"Co-immunoprecipitation (direct interaction), siRNA knockdown, confocal imaging, live-cell MT dynamics analysis","journal":"The Journal of cell biology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — co-IP for direct interaction, RNAi with phenotypic readout, single lab with multiple methods","pmids":["24368809"],"is_preprint":false},{"year":2013,"finding":"Protein 4.1R interacts and co-localizes with cortical CLASP2 and is required for correct number and dynamics of CLASP2 cortical platforms. 4.1R controls CLASP2 binding to MTs at the cell edge by locally altering GSK3 activity. Loss of 4.1R causes MT plus-ends to continue growing and bending rather than being tethered to the cortex.","method":"Co-immunoprecipitation, siRNA knockdown, confocal live imaging, GSK3 activity assays","journal":"Journal of cell science","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — co-IP, RNAi, live imaging, GSK3 activity measurement, single lab","pmids":["23943871"],"is_preprint":false},{"year":2014,"finding":"Abl tyrosine kinase binds to CLASP2 and phosphorylates it (Km ~1.89 µM) in response to serum or PDGF stimulation. Abl-phosphorylated tyrosine residues map within F-actin and MT plus-end interaction domains. Abl phosphorylation of CLASP2 modulates its direct binding to MTs and actin, and alters its localization and F-actin distribution in spinal cord growth cones.","method":"In vitro kinase assay with purified proteins, mass spectrometry phosphosite identification, co-immunoprecipitation, pulldown with purified proteins, confocal imaging","journal":"Cytoskeleton (Hoboken, N.J.)","confidence":"High","confidence_rationale":"Tier 1-2 / Moderate — in vitro kinase reconstitution with Km determination, MS phosphosite mapping, pulldown with purified proteins, cell imaging; single lab","pmids":["24520051"],"is_preprint":false},{"year":2014,"finding":"PAR3 directly interacts with CLASP2 and aPKC phosphorylates CLASP2. This phosphorylation inhibits the interaction between CLASP2 and GCC185 (a TGN protein). Loss of PAR3 or aPKC causes aberrant accumulation of CLASP2 at the TGN and disrupts Golgi ribbon organization. A CLASP2 mutant blocking PAR3 interaction disrupts Golgi organization.","method":"Co-immunoprecipitation, in vitro phosphorylation, dominant-negative mutants, siRNA knockdown, confocal imaging of Golgi","journal":"Molecular biology of the cell","confidence":"Medium","confidence_rationale":"Tier 1-2 / Moderate — direct interaction by co-IP, in vitro phosphorylation, mutagenesis, siRNA; single lab","pmids":["25518939"],"is_preprint":false},{"year":2015,"finding":"Crystal structures of the two TOG domains of CLASP2 reveal paddle-like tubulin-binding conformations with six HEAT repeats each, but with distinct degrees and directions of curvature. Biochemical and cell biological analyses show each TOG domain associates differently with αβ-tubulin, suggesting they discriminate between different states of MT dynamic instability.","method":"X-ray crystallography, biochemical binding assays, molecular modeling, cell biology analysis","journal":"Journal of molecular biology","confidence":"High","confidence_rationale":"Tier 1 / Moderate — crystal structures with functional biochemical validation, multiple methods; single lab","pmids":["26003921"],"is_preprint":false},{"year":2015,"finding":"CLASP2-mediated microtubule capture at NMJ AChR clusters requires the CLASP2-binding partner LL5β. Forced expression of a CLASP2 fragment blocking CLASP2/LL5β interaction inhibits MT capture and impairs focal vesicle delivery to clusters. LL5β knockdown at the NMJ in vivo reduces AChR density and insertion. MT and actin depolymerization also inhibit MT capture and focal vesicle delivery.","method":"RNAi knockdown of LL5β, dominant-negative CLASP2 fragment expression, live imaging of vesicle delivery, in vivo NMJ analysis","journal":"Molecular biology of the cell","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — domain-specific inhibition, RNAi, in vivo and in vitro readouts; single lab","pmids":["25589673"],"is_preprint":false},{"year":2017,"finding":"GSK3-mediated global phosphorylation of CLASP2α largely abolishes its microtubule association in metaphase but does not directly control its kinetochore localization. Phosphorylation-site mutants reveal that CLASP2α phosphorylation weakens kinetochore-MT interactions (reduced sister kinetochore tension) and increases chromosome segregation defects. A model is proposed where only kinetochore-bound CLASP2α is locally dephosphorylated to engage microtubule binding.","method":"Dominant phosphorylation-site variants (phosphomimetic and phospho-resistant), live-cell imaging, sister kinetochore tension measurements","journal":"Journal of cell science","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — phospho-site mutagenesis with defined mitotic phenotypes, single lab","pmids":["28232523"],"is_preprint":false},{"year":2017,"finding":"CLASP2 is a cytoskeletal effector in the Reelin signaling pathway. Reelin regulates phosphorylation of GSK3β consensus sites within the CLASP2 serine/arginine-rich region. CLASP2 phosphorylation status regulates its interaction with the Reelin adaptor Dab1, and this association is required for CLASP2 effects on neurite extension and motility during neocortical neuron migration.","method":"Co-immunoprecipitation, phosphorylation site mutagenesis, in utero electroporation knockdown, confocal imaging, neuron migration assays","journal":"Neuron","confidence":"High","confidence_rationale":"Tier 2 / Strong — co-IP for Dab1 interaction, phospho-site mutagenesis, in vivo knockdown with migration phenotype, multiple methods","pmids":["28285824"],"is_preprint":false},{"year":2017,"finding":"CLASP2 co-immunoprecipitates with SOGA1, MARK2, and G2L1 in 3T3-L1 adipocytes. Reciprocal co-IP confirmed CLASP2-MARK2 and CLASP2-SOGA1 interactions. SOGA1 co-localizes with CLASP2 and tubulin, identifying SOGA1 as a new microtubule-associated protein.","method":"Affinity purification-mass spectrometry (AP-MS), reciprocal co-immunoprecipitation, confocal co-localization","journal":"Molecular & cellular proteomics : MCP","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — AP-MS with reciprocal co-IP validation, single lab","pmids":["28550165"],"is_preprint":false},{"year":2018,"finding":"Purified human CLASP2 suppresses microtubule catastrophe and promotes rescue in vitro without affecting growth or shrinkage rates. Combined with EB1, CLASP2 effects are strongly enhanced in a manner dependent on direct CLASP2-EB1 interaction. EB1 targets CLASP2 to microtubules and increases its dwell time at microtubule tips.","method":"In vitro reconstitution with purified proteins, TIRF microscopy, truncated EB1 lacking CLASP2-binding domain as control","journal":"Molecular biology of the cell","confidence":"High","confidence_rationale":"Tier 1 / Strong — in vitro reconstitution with purified proteins, TIRF microscopy, domain-specific controls; rigorous biochemical study","pmids":["29540526"],"is_preprint":false},{"year":2020,"finding":"Human CLASP2 exists predominantly as a monomer in solution but can self-associate through its C-terminal kinetochore-binding domain. Kinetochore localization is independent of self-association. CLASP2 kinetochore localization, EB-protein interaction (for growing plus-end recognition), and association with curved microtubule protofilaments via TOG2 and TOG3 domains are each independently required for normal kinetochore-MT dynamics, spindle length, SAC satisfaction, and chromosome segregation.","method":"In vitro biophysical assays, domain mutant rescue experiments, kinetochore-MT half-life measurements, poleward flux measurements, FRAP","journal":"The Journal of cell biology","confidence":"High","confidence_rationale":"Tier 1-2 / Strong — domain dissection with rescue experiments, multiple independent functional readouts, quantitative biophysics; rigorous study","pmids":["31757788"],"is_preprint":false},{"year":2020,"finding":"CLASP2 is required for HIV-1 to induce microtubule stabilization and promote early infection in human microglia cells. CLASP2 binds to intact HIV-1 cores and in vitro-assembled capsid-nucleocapsid (CA-NC) complexes. The C-terminal domain of CLASP2 (which mediates host effector interactions) is specifically required for MT stabilization and early HIV-1 infection, but not for binding to HIV-1 cores.","method":"RNAi knockdown, fixed and live-cell imaging of HIV-1 particle trafficking, in vitro binding to assembled CA-NC complexes, C-terminal domain deletion mutant","journal":"Journal of virology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — direct binding assay to CA-NC complexes, domain mutant, RNAi with infection phenotype; single lab","pmids":["32376623"],"is_preprint":false},{"year":2020,"finding":"The combination of CLASP2 with EB1, XMAP215, and MCAK reconstitutes robust plus-end-leading microtubule treadmilling in vitro. CLASP2's catastrophe suppression and rescue promotion contribute to the dynamic balance enabling treadmilling.","method":"In vitro reconstitution with purified proteins (multi-MAP assay), TIRF microscopy, computational simulations","journal":"Proceedings of the National Academy of Sciences","confidence":"High","confidence_rationale":"Tier 1 / Strong — in vitro reconstitution with purified proteins, computational prediction confirmed experimentally, multiple orthogonal approaches","pmids":["32457163"],"is_preprint":false},{"year":2021,"finding":"SOCS3 interacts with CLASP2 and CLIP-170 via its N-terminal domain, forming a complex. This SOCS3-CLIP-170/CLASP2 complex is essential for maximal SOCS3 anti-inflammatory effects in lung endothelial cells. IL-6 and HKSA disrupt SOCS3 interaction with CLASP2/CLIP-170. CLASP2 knockdown impairs SOCS3-JAK2 interaction and abolishes anti-inflammatory effects of SOCS3.","method":"Co-immunoprecipitation, RNAi knockdown, MT fractionation, endothelial barrier assays, EC-specific SOCS3 KO mice","journal":"The Journal of biological chemistry","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — co-IP for interaction, RNAi with functional phenotypes, in vivo KO model; single lab","pmids":["33372035"],"is_preprint":false},{"year":2021,"finding":"LRAP35a promotes CLASP2/EB1 interaction for MT stabilization. Sequential phosphorylation of LRAP35a by PKA then GSK3β initiates LRAP35a-CLASP2 association. Subsequent CK1δ phosphorylation of CLASP2 (on GSK3β sites that block EB1 SxIP binding) is directly countered by LRAP35a interaction competing for CK1δ activity, thus regulating MT dynamics during cell migration.","method":"Co-immunoprecipitation, phospho-site mutagenesis, kinase inhibition, live-cell MT dynamics imaging","journal":"Cell reports","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — co-IP, mutagenesis, pharmacological kinase manipulation; single lab with multiple methods","pmids":["34525355"],"is_preprint":false},{"year":2023,"finding":"CLASP2α directly cross-links F-actin to the microtubule lattice in vitro. A minimal construct L-TOG2-S (containing TOG2 domain and serine-arginine-rich region) retains this cross-linking ability. CLASP2α promotes accumulation of multiple actin filaments along a single microtubule, and depletion of CLASPs in vascular smooth muscle cells causes disorganized actin fibers and reduced co-alignment with microtubules.","method":"In vitro reconstitution with purified proteins, TIRF microscopy, CLASP2 depletion in VSMCs, confocal imaging","journal":"Molecular biology of the cell","confidence":"High","confidence_rationale":"Tier 1-2 / Strong — in vitro reconstitution with purified proteins, domain dissection (minimal construct), cellular KD with phenotypic readout; multiple methods","pmids":["36598814"],"is_preprint":false},{"year":2023,"finding":"CLASP2 forms a load-bearing bond with terminal non-GTP tubulins at stabilized microtubule tips using its TOG2 domain. TOG2 releases its high-affinity bond upon conversion of non-GTP dimers to polymerization-competent GTP-tubulins. This nucleotide-state-sensitive recognition of curved protofilaments suppresses catastrophe and promotes persistent tubulin assembly at load-bearing (e.g., kinetochore) ends.","method":"DNA origami-based reconstruction assays, in vitro biochemical assays, nucleotide exchange experiments, force measurement","journal":"Science advances","confidence":"High","confidence_rationale":"Tier 1 / Strong — DNA origami reconstitution with load-bearing measurements, domain-specific (TOG2) functional dissection, nucleotide-state specificity demonstrated biochemically; rigorous study","pmids":["36598991"],"is_preprint":false},{"year":2009,"finding":"FEZ1 and CLASP2 interact through coiled-coil regions in vitro, co-localize with NEK1 in a perinuclear/centrosomal region, and all three interact with endogenous gamma-tubulin. CLASP2 is phosphorylated by and interacts with active PKC isoforms; PMA treatment inhibits FEZ1/CLASP2 co-localization.","method":"Co-immunoprecipitation, in vitro coiled-coil interaction assay, immunofluorescence co-localization, PMA treatment","journal":"Molecular and cellular biochemistry","confidence":"Low","confidence_rationale":"Tier 3 / Weak — single co-IP/pulldown, co-localization only, single lab with limited mechanistic follow-up","pmids":["19924516"],"is_preprint":false},{"year":2014,"finding":"GSK3β phosphorylation of CLASP2 regulates AChR cluster size at the NMJ: a nonphosphorylatable CLASP2 mutant (9XS/9XA) promotes MT capture and increases AChR cluster size, while a phosphomimetic mutant (8XS/D) reduces MT capture and AChR cluster size despite enrichment at clusters.","method":"Expression of phosphomimetic and phospho-resistant CLASP2 mutants in myotubes on agrin patches, live MT imaging, quantitative AChR cluster analysis","journal":"The Journal of biological chemistry","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — bidirectional mutagenesis (phosphomimetic vs phospho-resistant) with functional MT capture and receptor density readouts; single lab","pmids":["25231989"],"is_preprint":false},{"year":2025,"finding":"CLASP2 directly interacts with IQGAP1 to regulate F-actin cytoskeleton remodeling in bladder cancer cells. TNF-α promotes METTL3-mediated m6A modification of CLASP2 mRNA, enhancing its stability and increasing CLASP2 protein levels, which drives CLASP2-IQGAP1-dependent F-actin reorganization and metastasis.","method":"Co-immunoprecipitation (Co-IP), MeRIP for m6A detection, immunofluorescence, siRNA knockdown, xenograft mouse model","journal":"Biochimica et biophysica acta. Molecular basis of disease","confidence":"Medium","confidence_rationale":"Tier 2-3 / Moderate — co-IP for CLASP2-IQGAP1 interaction, MeRIP for m6A, RNAi with functional readouts; single lab","pmids":["40118293"],"is_preprint":false}],"current_model":"CLASP2 is a microtubule plus-end tracking protein that suppresses catastrophe and promotes rescue by binding non-GTP tubulins at curved protofilament tips via its TOG2 domain, tracks growing MT ends through direct EB1 interaction (via SXIP motifs), and cross-links F-actin to the MT lattice via its TOG2 and serine-arginine-rich region; its activity is spatiotemporally controlled by multisite phosphorylation from GSK3β (disrupting EB1/IQGAP1/MT binding), Cdk1/Plk1 (regulating kinetochore-MT attachment stability during mitosis), aPKC (controlling Golgi organization via GCC185 interaction), and Abl (modulating actin/MT binding at growth cones), while at the cell cortex CLASP2 captures MT plus-ends through LL5β and protein 4.1R to direct GLUT4 vesicle delivery, acetylcholine receptor insertion at the NMJ, and directional cell migration."},"narrative":{"mechanistic_narrative":"CLASP2 is a microtubule plus-end tracking protein that stabilizes microtubules by suppressing catastrophe and promoting rescue, and that cross-links the actin and microtubule cytoskeletons to organize polarized cell behaviors [PMID:29540526, PMID:36598814]. Purified CLASP2 intrinsically suppresses catastrophe and promotes rescue without altering growth or shrinkage rates, and its activity is targeted and amplified by direct binding to EB1, which delivers CLASP2 to and prolongs its dwell at growing plus-ends [PMID:29540526]; together with EB1, XMAP215, and MCAK it reconstitutes plus-end-leading microtubule treadmilling in vitro [PMID:32457163]. Mechanistically, its tandem TOG domains adopt distinct curved tubulin-binding conformations that discriminate states of dynamic instability, and the TOG2 domain forms a load-bearing, nucleotide-state-sensitive bond with terminal non-GTP tubulins at curved protofilament tips, releasing upon conversion to GTP-tubulin to enable persistent assembly at load-bearing ends [PMID:26003921, PMID:36598991]. CLASP2 cross-links F-actin to the microtubule lattice through a minimal TOG2 plus serine-arginine-rich module [PMID:36598814]. This activity is gated by multisite phosphorylation: GSK3β phosphorylation near the SXIP EB1-binding motifs disrupts the salt-bridge interactions required for EB1 binding and abolishes plus-end tracking, with CDK priming required beforehand [PMID:22467876, PMID:19638411], while Cdk1 priming and Plk1 act during mitosis to stabilize kinetochore-microtubule attachments [PMID:23045552]. At kinetochores, centrosomes, and the spindle, CLASP2 is required for chromosome segregation and spindle integrity, with kinetochore localization, EB-protein binding, and TOG-mediated recognition of curved protofilaments each independently necessary for normal kinetochore-MT dynamics [PMID:16914514, PMID:31757788]. At the cell cortex, CLASP2 captures and tethers microtubule plus-ends through partners including LL5β and protein 4.1R to direct focal vesicle delivery and AChR insertion at the neuromuscular junction and insulin-stimulated GLUT4 delivery, and it drives persistent directional migration via cortical localization controlled by ACF7 [PMID:25589673, PMID:23943871, PMID:22992739, PMID:17113391]. CLASP2 additionally functions as a cytoskeletal effector in Reelin/Dab1 signaling during neocortical neuron migration and regulates neuronal polarity and synapse formation [PMID:28285824, PMID:23035100].","teleology":[{"year":2005,"claim":"Established how CLASP2 stabilizes microtubules: by directly binding EB1 and tethering microtubules to the cell cortex, confining dynamics to the cell periphery.","evidence":"RNAi, direct binding assays, domain deletion, and live imaging in HeLa cells","pmids":["15631994"],"confidence":"High","gaps":["Identity of the cortical anchor undefined at this stage","No in vitro reconstitution of stabilization activity"]},{"year":2006,"claim":"Defined CLASP2's cellular roles in polarized motility and in mitosis, placing ACF7 upstream of its cortical localization and demonstrating segregation/spindle requirements.","evidence":"CLASP2 knockout MEFs in wound-healing and mitotic assays, FRAP, ACF7 RNAi","pmids":["17113391","16914514"],"confidence":"High","gaps":["Molecular link between ACF7 and CLASP2 cortical capture unresolved","Kinetochore recruitment mechanism unknown"]},{"year":2007,"claim":"Showed CLASP2 is an actin/microtubule crosslinker, mapping actin-binding to its MT-binding and N-terminal TOG domains.","evidence":"Co-IP, deletion mapping, and FRET in Xenopus fibroblasts/neurons","pmids":["17342765"],"confidence":"Medium","gaps":["Crosslinking not reconstituted with purified proteins","Functional consequence of actin binding not established"]},{"year":2009,"claim":"Identified GSK3β as a direct regulator that switches off CLASP2 by phosphorylating Ser533/Ser537 to dissociate it from EB1, IQGAP1, and microtubules, establishing phospho-gating of plus-end tracking.","evidence":"In vitro phosphorylation, mutagenesis, co-IP, imaging in migrating fibroblasts","pmids":["19638411"],"confidence":"High","gaps":["Phosphatase that reverses the mark unidentified","Spatial control of GSK3β activity not defined"]},{"year":2012,"claim":"Resolved the structural logic of phospho-control and extended it to mitosis: GSK3 multisite phosphorylation disrupts SXIP salt-bridge contacts (with CDK priming) and Cdk1/Plk1 cascades stabilize kinetochore-MT attachments.","evidence":"In vitro binding, 31P NMR, MD simulations, phospho-site mutagenesis, kinase assays, live imaging","pmids":["22467876","23045552"],"confidence":"High","gaps":["How local dephosphorylation is achieved at specific sites unclear","Integration of multiple kinase inputs in vivo not fully mapped"]},{"year":2012,"claim":"Connected CLASP2 to physiological cortical capture: agrin/PI3K/GSK3β signaling licenses CLASP2 to capture plus-ends at AChR clusters, and CLASP2 controls neuronal polarity and synapse formation.","evidence":"RNAi/overexpression in myotubes and neurons, pharmacological pathway manipulation, electrophysiology, imaging","pmids":["22851317","23035100"],"confidence":"High","gaps":["Cortical receptor linking CLASP2 to AChR clusters not yet identified here","Mechanism coupling capture to subsynaptic gene expression unknown"]},{"year":2012,"claim":"Linked CLASP2 to metabolic vesicle delivery, showing insulin-stimulated phosphorylation and a requirement for insulin-stimulated GLUT4 delivery and glucose transport.","evidence":"Mass spectrometry, phosphoantibody IP, siRNA, glucose transport assay in myotubes/adipocytes","pmids":["22992739"],"confidence":"Medium","gaps":["Insulin-responsive kinase site not defined","Direct role at GLUT4 vesicle docking versus indirect not separated"]},{"year":2013,"claim":"Identified cortical/junctional partners (p120-catenin, protein 4.1R) that recruit CLASP2 and locally tune GSK3 to govern microtubule tethering at the cell edge and adherens junctions.","evidence":"Co-IP, siRNA, live MT dynamics imaging, GSK3 activity assays","pmids":["24368809","23943871"],"confidence":"Medium","gaps":["Whether 4.1R/p120 interactions are direct or scaffolded not fully resolved","Mechanism of local GSK3 regulation by 4.1R unclear"]},{"year":2014,"claim":"Expanded the kinase repertoire and structural basis: Abl phosphorylates CLASP2 within actin/MT-binding domains to modulate growth-cone cytoskeleton, aPKC/PAR3 control Golgi organization via GCC185, and TOG crystal structures reveal distinct tubulin-binding curvatures.","evidence":"In vitro kinase assays, MS phosphosite mapping, co-IP, X-ray crystallography, mutagenesis","pmids":["24520051","25518939","26003921","25231989"],"confidence":"High","gaps":["How distinct TOG conformations map to specific dynamic-instability states not directly demonstrated in cells","Crosstalk among Abl/aPKC/GSK3 inputs unresolved"]},{"year":2015,"claim":"Established LL5β as the cortical partner required for CLASP2-mediated MT capture and focal vesicle delivery at the NMJ.","evidence":"LL5β RNAi, dominant-negative CLASP2 fragment, live vesicle imaging, in vivo NMJ analysis","pmids":["25589673"],"confidence":"Medium","gaps":["Whether CLASP2-LL5β binding is direct not established here","Cargo specificity of focal delivery undefined"]},{"year":2017,"claim":"Demonstrated CLASP2 acts as a cytoskeletal effector in Reelin signaling via phospho-regulated Dab1 association, and refined the kinetochore phospho-model where only kinetochore-bound CLASP2 is locally dephosphorylated.","evidence":"Co-IP, phospho-site mutagenesis, in utero electroporation, migration assays, kinetochore tension measurements","pmids":["28285824","28232523"],"confidence":"Medium","gaps":["Phosphatase mediating local kinetochore dephosphorylation unidentified","Direct Dab1-CLASP2 contact interface not mapped"]},{"year":2018,"claim":"Reconstituted CLASP2's intrinsic activity, proving it suppresses catastrophe and promotes rescue and that EB1 targets it to and prolongs its dwell at MT tips through direct interaction.","evidence":"In vitro reconstitution with purified proteins, TIRF microscopy, EB1 truncation controls","pmids":["29540526"],"confidence":"High","gaps":["Stoichiometry of the CLASP2-EB1-MT complex not defined","Which TOG domain mediates rescue not resolved here"]},{"year":2020,"claim":"Dissected CLASP2's molecular determinants in mitosis (independent requirements for kinetochore localization, EB binding, and TOG2/TOG3 protofilament recognition), defined treadmilling reconstitution, and uncovered roles in HIV-1 infection.","evidence":"Domain-mutant rescue, biophysics, FRAP; multi-MAP in vitro reconstitution; HIV-1 binding and infection assays","pmids":["31757788","32457163","32376623"],"confidence":"High","gaps":["How the three activities are coordinated temporally at kinetochores unclear","Functional consequence of C-terminal self-association unknown"]},{"year":2023,"claim":"Defined the biophysical mechanism of stabilization: TOG2 forms a load-bearing, nucleotide-state-sensitive bond with terminal non-GTP tubulins at curved protofilaments, and reconstituted actin-MT crosslinking via a minimal TOG2/SR module.","evidence":"DNA origami reconstitution with force measurement, nucleotide exchange, in vitro crosslinking, VSMC depletion","pmids":["36598991","36598814"],"confidence":"High","gaps":["How load-bearing tip binding is integrated with EB1-mediated tip tracking unresolved","In vivo contribution of crosslinking to specific tissues limited"]},{"year":2025,"claim":"Extended CLASP2 regulation to RNA-level control and disease, showing TNF-α/METTL3 m6A stabilization of CLASP2 mRNA driving CLASP2-IQGAP1-dependent actin remodeling and metastasis.","evidence":"Co-IP, MeRIP, siRNA, xenograft model in bladder cancer cells","pmids":["40118293"],"confidence":"Medium","gaps":["Direct versus scaffolded CLASP2-IQGAP1 interaction in this context not separated","Causal contribution of m6A site to phenotype not isolated"]},{"year":null,"claim":"How CLASP2's distinct activities — intrinsic tip stabilization, EB-mediated tracking, actin crosslinking, and cortical capture — are integrated and switched by competing phospho-inputs in a single cell remains unresolved.","evidence":"","pmids":[],"confidence":"Medium","gaps":["No unified model coupling kinase inputs to spatial activity states","Phosphatases reversing GSK3/Cdk1/Plk1 marks largely unidentified","Quantitative hierarchy of cortical partners in different tissues undefined"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0008092","term_label":"cytoskeletal protein binding","supporting_discovery_ids":[3,19,22,25,26]},{"term_id":"GO:0060090","term_label":"molecular adaptor activity","supporting_discovery_ids":[0,11,15,25]}],"localization":[{"term_id":"GO:0005856","term_label":"cytoskeleton","supporting_discovery_ids":[0,19,25]},{"term_id":"GO:0005886","term_label":"plasma membrane","supporting_discovery_ids":[0,9,15]},{"term_id":"GO:0005815","term_label":"microtubule organizing center","supporting_discovery_ids":[2,27]},{"term_id":"GO:0005794","term_label":"Golgi apparatus","supporting_discovery_ids":[13]}],"pathway":[{"term_id":"R-HSA-1640170","term_label":"Cell Cycle","supporting_discovery_ids":[2,5,16,20]},{"term_id":"R-HSA-9609507","term_label":"Protein localization","supporting_discovery_ids":[9,15]},{"term_id":"R-HSA-162582","term_label":"Signal Transduction","supporting_discovery_ids":[7,17,23]},{"term_id":"R-HSA-1266738","term_label":"Developmental Biology","supporting_discovery_ids":[8,17]}],"complexes":["kinetochore"],"partners":["EB1","IQGAP1","LL5B","EPB41","PARD3","DAB1","CLIP1","MARK2"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"O75122","full_name":"CLIP-associating protein 2","aliases":["Cytoplasmic linker-associated protein 2","Protein Orbit homolog 2","hOrbit2"],"length_aa":1294,"mass_kda":141.1,"function":"Microtubule plus-end tracking protein that promotes the stabilization of dynamic microtubules (PubMed:26003921). Involved in the nucleation of noncentrosomal microtubules originating from the trans-Golgi network (TGN). Required for the polarization of the cytoplasmic microtubule arrays in migrating cells towards the leading edge of the cell. May act at the cell cortex to enhance the frequency of rescue of depolymerizing microtubules by attaching their plus-ends to cortical platforms composed of ERC1 and PHLDB2 (PubMed:16824950). This cortical microtubule stabilizing activity is regulated at least in part by phosphatidylinositol 3-kinase signaling. Also performs a similar stabilizing function at the kinetochore which is essential for the bipolar alignment of chromosomes on the mitotic spindle (PubMed:16866869, PubMed:16914514). Acts as a mediator of ERBB2-dependent stabilization of microtubules at the cell cortex","subcellular_location":"Cytoplasm, cytoskeleton; Cytoplasm, cytoskeleton, microtubule organizing center, centrosome; Chromosome, centromere, kinetochore; Cytoplasm, cytoskeleton, spindle; Golgi apparatus; Golgi apparatus, trans-Golgi network; Cell membrane; Cell projection, ruffle membrane; Cytoplasm, cell cortex","url":"https://www.uniprot.org/uniprotkb/O75122/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/CLASP2","classification":"Not Classified","n_dependent_lines":14,"n_total_lines":77,"dependency_fraction":0.18181818181818182},"opencell":{"profiled":true,"resolved_as":"","ensg_id":"ENSG00000163539","cell_line_id":"CID001506","localizations":[{"compartment":"cytoskeleton","grade":3},{"compartment":"golgi","grade":3},{"compartment":"cytoplasmic","grade":2}],"interactors":[{"gene":"GCC2","stoichiometry":10.0},{"gene":"CENPJ","stoichiometry":4.0},{"gene":"JAKMIP1","stoichiometry":4.0},{"gene":"CLASP1","stoichiometry":0.2},{"gene":"YWHAZ","stoichiometry":0.2},{"gene":"DYNLT1","stoichiometry":0.2},{"gene":"YWHAH","stoichiometry":0.2},{"gene":"ACTR1A","stoichiometry":0.2},{"gene":"YWHAG","stoichiometry":0.2},{"gene":"YWHAE","stoichiometry":0.2}],"url":"https://opencell.sf.czbiohub.org/target/CID001506","total_profiled":1310},"omim":[{"mim_id":"620225","title":"SUPPRESSOR OF GLUCOSE, AUTOPHAGY-ASSOCIATED PROTEIN 1; SOGA1","url":"https://www.omim.org/entry/620225"},{"mim_id":"605853","title":"CYTOPLASMIC LINKER-ASSOCIATED PROTEIN 2; CLASP2","url":"https://www.omim.org/entry/605853"},{"mim_id":"605852","title":"CYTOPLASMIC LINKER-ASSOCIATED PROTEIN 1; CLASP1","url":"https://www.omim.org/entry/605852"},{"mim_id":"604696","title":"A-KINASE ANCHOR PROTEIN 11; AKAP11","url":"https://www.omim.org/entry/604696"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Supported","locations":[{"location":"Golgi apparatus","reliability":"Supported"},{"location":"Cytosol","reliability":"Additional"}],"tissue_specificity":"Tissue enhanced","tissue_distribution":"Detected in all","driving_tissues":[{"tissue":"brain","ntpm":105.5},{"tissue":"retina","ntpm":117.3}],"url":"https://www.proteinatlas.org/search/CLASP2"},"hgnc":{"alias_symbol":["KIAA0627"],"prev_symbol":[]},"alphafold":{"accession":"O75122","domains":[{"cath_id":"1.25.10.10","chopping":"68-308","consensus_level":"medium","plddt":95.8382,"start":68,"end":308},{"cath_id":"1.25.10.10","chopping":"653-769","consensus_level":"medium","plddt":89.0308,"start":653,"end":769},{"cath_id":"1.25.10.10","chopping":"776-878","consensus_level":"medium","plddt":91.5613,"start":776,"end":878},{"cath_id":"-","chopping":"1203-1280","consensus_level":"medium","plddt":90.1144,"start":1203,"end":1280},{"cath_id":"1.20.930","chopping":"1070-1175","consensus_level":"medium","plddt":89.3986,"start":1070,"end":1175}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/O75122","model_url":"https://alphafold.ebi.ac.uk/files/AF-O75122-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-O75122-F1-predicted_aligned_error_v6.png","plddt_mean":65.69},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=CLASP2","jax_strain_url":"https://www.jax.org/strain/search?query=CLASP2"},"sequence":{"accession":"O75122","fasta_url":"https://rest.uniprot.org/uniprotkb/O75122.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/O75122/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/O75122"}},"corpus_meta":[{"pmid":"15631994","id":"PMC_15631994","title":"CLASP1 and CLASP2 bind to EB1 and regulate microtubule plus-end dynamics at the cell cortex.","date":"2005","source":"The Journal of cell biology","url":"https://pubmed.ncbi.nlm.nih.gov/15631994","citation_count":336,"is_preprint":false},{"pmid":"17113391","id":"PMC_17113391","title":"Role of CLASP2 in microtubule stabilization and the regulation of persistent motility.","date":"2006","source":"Current biology : CB","url":"https://pubmed.ncbi.nlm.nih.gov/17113391","citation_count":132,"is_preprint":false},{"pmid":"19638411","id":"PMC_19638411","title":"Phosphorylation of CLASP2 by GSK-3beta regulates its interaction with IQGAP1, EB1 and microtubules.","date":"2009","source":"Journal of cell science","url":"https://pubmed.ncbi.nlm.nih.gov/19638411","citation_count":110,"is_preprint":false},{"pmid":"16914514","id":"PMC_16914514","title":"Mammalian CLASP1 and CLASP2 cooperate to ensure mitotic fidelity by regulating spindle and kinetochore function.","date":"2006","source":"Molecular biology of the cell","url":"https://pubmed.ncbi.nlm.nih.gov/16914514","citation_count":101,"is_preprint":false},{"pmid":"23045552","id":"PMC_23045552","title":"Cdk1 and Plk1 mediate a CLASP2 phospho-switch that stabilizes kinetochore-microtubule attachments.","date":"2012","source":"The Journal of cell biology","url":"https://pubmed.ncbi.nlm.nih.gov/23045552","citation_count":79,"is_preprint":false},{"pmid":"17342765","id":"PMC_17342765","title":"Microtubule-binding proteins CLASP1 and CLASP2 interact with actin filaments.","date":"2007","source":"Cell motility and the cytoskeleton","url":"https://pubmed.ncbi.nlm.nih.gov/17342765","citation_count":76,"is_preprint":false},{"pmid":"24923837","id":"PMC_24923837","title":"Neuronal deletion of GSK3β increases microtubule speed in the growth cone and enhances axon regeneration via CRMP-2 and independently of MAP1B and CLASP2.","date":"2014","source":"BMC biology","url":"https://pubmed.ncbi.nlm.nih.gov/24923837","citation_count":73,"is_preprint":false},{"pmid":"22467876","id":"PMC_22467876","title":"Multisite phosphorylation disrupts arginine-glutamate salt bridge networks required for binding of cytoplasmic linker-associated protein 2 (CLASP2) to end-binding protein 1 (EB1).","date":"2012","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/22467876","citation_count":67,"is_preprint":false},{"pmid":"29540526","id":"PMC_29540526","title":"Human CLASP2 specifically regulates microtubule catastrophe and rescue.","date":"2018","source":"Molecular biology of the cell","url":"https://pubmed.ncbi.nlm.nih.gov/29540526","citation_count":60,"is_preprint":false},{"pmid":"28550165","id":"PMC_28550165","title":"Characterization of the CLASP2 Protein Interaction Network Identifies SOGA1 as a Microtubule-Associated Protein.","date":"2017","source":"Molecular & cellular proteomics : MCP","url":"https://pubmed.ncbi.nlm.nih.gov/28550165","citation_count":50,"is_preprint":false},{"pmid":"22851317","id":"PMC_22851317","title":"Agrin regulates CLASP2-mediated capture of microtubules at the neuromuscular junction synaptic membrane.","date":"2012","source":"The Journal of cell biology","url":"https://pubmed.ncbi.nlm.nih.gov/22851317","citation_count":50,"is_preprint":false},{"pmid":"23035100","id":"PMC_23035100","title":"Microtubule plus-end tracking protein CLASP2 regulates neuronal polarity and synaptic function.","date":"2012","source":"The Journal of neuroscience : the official journal of the Society for Neuroscience","url":"https://pubmed.ncbi.nlm.nih.gov/23035100","citation_count":42,"is_preprint":false},{"pmid":"28285824","id":"PMC_28285824","title":"CLASP2 Links Reelin to the Cytoskeleton during Neocortical Development.","date":"2017","source":"Neuron","url":"https://pubmed.ncbi.nlm.nih.gov/28285824","citation_count":34,"is_preprint":false},{"pmid":"28232523","id":"PMC_28232523","title":"GSK3-mediated CLASP2 phosphorylation modulates kinetochore dynamics.","date":"2017","source":"Journal of cell science","url":"https://pubmed.ncbi.nlm.nih.gov/28232523","citation_count":30,"is_preprint":false},{"pmid":"25589673","id":"PMC_25589673","title":"CLASP2-dependent microtubule capture at the neuromuscular junction membrane requires LL5β and actin for focal delivery of acetylcholine receptor vesicles.","date":"2015","source":"Molecular biology of the cell","url":"https://pubmed.ncbi.nlm.nih.gov/25589673","citation_count":30,"is_preprint":false},{"pmid":"26003921","id":"PMC_26003921","title":"CLASP2 Has Two Distinct TOG Domains That Contribute Differently to Microtubule Dynamics.","date":"2015","source":"Journal of molecular biology","url":"https://pubmed.ncbi.nlm.nih.gov/26003921","citation_count":29,"is_preprint":false},{"pmid":"24368809","id":"PMC_24368809","title":"CLASP2 interacts with p120-catenin and governs microtubule dynamics at adherens junctions.","date":"2013","source":"The Journal of cell biology","url":"https://pubmed.ncbi.nlm.nih.gov/24368809","citation_count":27,"is_preprint":false},{"pmid":"31757788","id":"PMC_31757788","title":"CLASP2 binding to curved microtubule tips promotes flux and stabilizes kinetochore attachments.","date":"2020","source":"The Journal of cell biology","url":"https://pubmed.ncbi.nlm.nih.gov/31757788","citation_count":25,"is_preprint":false},{"pmid":"24520051","id":"PMC_24520051","title":"Abelson phosphorylation of CLASP2 modulates its association with microtubules and actin.","date":"2014","source":"Cytoskeleton (Hoboken, N.J.)","url":"https://pubmed.ncbi.nlm.nih.gov/24520051","citation_count":25,"is_preprint":false},{"pmid":"32376623","id":"PMC_32376623","title":"HIV-1 Exploits CLASP2 To Induce Microtubule Stabilization and Facilitate Virus Trafficking to the Nucleus.","date":"2020","source":"Journal of virology","url":"https://pubmed.ncbi.nlm.nih.gov/32376623","citation_count":21,"is_preprint":false},{"pmid":"22992739","id":"PMC_22992739","title":"Identification of a role for CLASP2 in insulin action.","date":"2012","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/22992739","citation_count":18,"is_preprint":false},{"pmid":"28166762","id":"PMC_28166762","title":"CLASP2 is involved in the EMT and early progression after transurethral resection of the bladder tumor.","date":"2017","source":"BMC cancer","url":"https://pubmed.ncbi.nlm.nih.gov/28166762","citation_count":18,"is_preprint":false},{"pmid":"25518939","id":"PMC_25518939","title":"PAR3 and aPKC regulate Golgi organization through CLASP2 phosphorylation to generate cell polarity.","date":"2014","source":"Molecular biology of the cell","url":"https://pubmed.ncbi.nlm.nih.gov/25518939","citation_count":17,"is_preprint":false},{"pmid":"25231989","id":"PMC_25231989","title":"Acetylcholine receptor (AChR) clustering is regulated both by glycogen synthase kinase 3β (GSK3β)-dependent phosphorylation and the level of CLIP-associated protein 2 (CLASP2) mediating the capture of microtubule plus-ends.","date":"2014","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/25231989","citation_count":17,"is_preprint":false},{"pmid":"23084744","id":"PMC_23084744","title":"The microtubule plus-end tracking protein CLASP2 is required for hematopoiesis and hematopoietic stem cell maintenance.","date":"2012","source":"Cell reports","url":"https://pubmed.ncbi.nlm.nih.gov/23084744","citation_count":16,"is_preprint":false},{"pmid":"23943871","id":"PMC_23943871","title":"Protein 4.1R binds to CLASP2 and regulates dynamics, organization and attachment of microtubules to the cell cortex.","date":"2013","source":"Journal of cell science","url":"https://pubmed.ncbi.nlm.nih.gov/23943871","citation_count":16,"is_preprint":false},{"pmid":"33372035","id":"PMC_33372035","title":"SOCS3-microtubule interaction via CLIP-170 and CLASP2 is critical for modulation of endothelial inflammation and lung injury.","date":"2021","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/33372035","citation_count":16,"is_preprint":false},{"pmid":"19924516","id":"PMC_19924516","title":"FEZ1 interacts with CLASP2 and NEK1 through coiled-coil regions and their cellular colocalization suggests centrosomal functions and regulation by PKC.","date":"2009","source":"Molecular and cellular biochemistry","url":"https://pubmed.ncbi.nlm.nih.gov/19924516","citation_count":15,"is_preprint":false},{"pmid":"36598814","id":"PMC_36598814","title":"CLASP2 facilitates dynamic actin filament organization along the microtubule lattice.","date":"2023","source":"Molecular biology of the cell","url":"https://pubmed.ncbi.nlm.nih.gov/36598814","citation_count":13,"is_preprint":false},{"pmid":"32457163","id":"PMC_32457163","title":"Collective effects of XMAP215, EB1, CLASP2, and MCAK lead to robust microtubule treadmilling.","date":"2020","source":"Proceedings of the National Academy of Sciences of the United States of America","url":"https://pubmed.ncbi.nlm.nih.gov/32457163","citation_count":13,"is_preprint":false},{"pmid":"36598991","id":"PMC_36598991","title":"CLASP2 recognizes tubulins exposed at the microtubule plus-end in a nucleotide state-sensitive manner.","date":"2023","source":"Science advances","url":"https://pubmed.ncbi.nlm.nih.gov/36598991","citation_count":13,"is_preprint":false},{"pmid":"33776760","id":"PMC_33776760","title":"Circ_CLASP2 Regulates High Glucose-Induced Dysfunction of Human Endothelial Cells Through Targeting miR-140-5p/FBXW7 Axis.","date":"2021","source":"Frontiers in pharmacology","url":"https://pubmed.ncbi.nlm.nih.gov/33776760","citation_count":11,"is_preprint":false},{"pmid":"24127197","id":"PMC_24127197","title":"Interstitial deletion of 3p22.3p22.2 encompassing ARPP21 and CLASP2 is a potential pathogenic factor for a syndromic form of intellectual disability: a co-morbidity model with additional copy number variations in a large family.","date":"2013","source":"American journal of medical genetics. Part A","url":"https://pubmed.ncbi.nlm.nih.gov/24127197","citation_count":11,"is_preprint":false},{"pmid":"16123238","id":"PMC_16123238","title":"PAR-1 and the microtubule-associated proteins CLASP2 and dynactin-p50 have specific localisation on mouse meiotic and first mitotic spindles.","date":"2005","source":"Reproduction (Cambridge, England)","url":"https://pubmed.ncbi.nlm.nih.gov/16123238","citation_count":9,"is_preprint":false},{"pmid":"35705037","id":"PMC_35705037","title":"CLASP2 safeguards hematopoietic stem cell properties during mouse and fish development.","date":"2022","source":"Cell reports","url":"https://pubmed.ncbi.nlm.nih.gov/35705037","citation_count":8,"is_preprint":false},{"pmid":"24994500","id":"PMC_24994500","title":"A lack of association between polymorphisms of three positional candidate genes (CLASP2 , UBP1, and FBXL2) and canine disorder of sexual development (78,XX; SRY -negative).","date":"2014","source":"Sexual development : genetics, molecular biology, evolution, endocrinology, embryology, and pathology of sex determination and differentiation","url":"https://pubmed.ncbi.nlm.nih.gov/24994500","citation_count":7,"is_preprint":false},{"pmid":"40118293","id":"PMC_40118293","title":"TNF-α drives bladder cancer metastasis via METTL3-mediated m6A modification to promote CLASP2/IQGAP1-dependent cytoskeleton remodeling.","date":"2025","source":"Biochimica et biophysica acta. Molecular basis of disease","url":"https://pubmed.ncbi.nlm.nih.gov/40118293","citation_count":6,"is_preprint":false},{"pmid":"30835922","id":"PMC_30835922","title":"Exogenous CLASP2 protein treatment enhances wound healing in vitro and in vivo.","date":"2019","source":"Wound repair and regeneration : official publication of the Wound Healing Society [and] the European Tissue Repair Society","url":"https://pubmed.ncbi.nlm.nih.gov/30835922","citation_count":5,"is_preprint":false},{"pmid":"28069833","id":"PMC_28069833","title":"Clasp2 ensures mitotic fidelity and prevents differentiation of epidermal keratinocytes.","date":"2017","source":"Journal of cell science","url":"https://pubmed.ncbi.nlm.nih.gov/28069833","citation_count":2,"is_preprint":false},{"pmid":"34525355","id":"PMC_34525355","title":"Cyclical phosphorylation of LRAP35a and CLASP2 by GSK3β and CK1δ regulates EB1-dependent MT dynamics in cell migration.","date":"2021","source":"Cell reports","url":"https://pubmed.ncbi.nlm.nih.gov/34525355","citation_count":2,"is_preprint":false},{"pmid":"40382315","id":"PMC_40382315","title":"KHSRP promotes the malignant behavior and cisplatin resistance of bladder cancer cells through the CLASP2/MAPRE1 axis.","date":"2025","source":"The pharmacogenomics journal","url":"https://pubmed.ncbi.nlm.nih.gov/40382315","citation_count":1,"is_preprint":false},{"pmid":"38066968","id":"PMC_38066968","title":"Analysis of clasp2 Transcription Pattern in Male Germ Cells during Spermatogenesis: A Comparative Study in Zebrafish (Danio rerio) and Guppy (Poecilia reticulata).","date":"2023","source":"Animals : an open access journal from MDPI","url":"https://pubmed.ncbi.nlm.nih.gov/38066968","citation_count":0,"is_preprint":false},{"pmid":null,"id":"bio_10.1101_2025.08.12.669862","title":"Suppressing microtubule detyrosination augments AAV2 endosomal escape and gene delivery","date":"2025-08-13","source":"bioRxiv","url":"https://doi.org/10.1101/2025.08.12.669862","citation_count":0,"is_preprint":true}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":23004,"output_tokens":7749,"usd":0.092623,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":17264,"output_tokens":5217,"usd":0.108372,"stage2_stop_reason":"end_turn"},"total_usd":0.200995,"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\": 2005,\n      \"finding\": \"CLASP1 and CLASP2 bind directly to EB1 via their middle domain, and CLASP2 associates with the cell cortex through its C-terminal domain in an MT-independent manner. Both EB1-binding and cortex-binding domains are required for MT stabilization. CLASPs stabilize MTs by promoting pauses and restricting growth/shortening episodes to the cell periphery.\",\n      \"method\": \"RNA interference in HeLa cells, direct binding assays, live-cell fluorescence imaging, domain deletion analysis\",\n      \"journal\": \"The Journal of cell biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — reciprocal binding assays, RNAi phenotype, domain mapping with multiple orthogonal methods, replicated across labs\",\n      \"pmids\": [\"15631994\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2006,\n      \"finding\": \"CLASP2 is required for formation of a stable, polarized microtubule array at the leading edge of migrating fibroblasts and for persistent directional motility. ACF7 acts upstream of CLASP2 by regulating its cortical localization. CLASP2 is immobilized in a bimodal manner near cell edges to stabilize MTs.\",\n      \"method\": \"Mouse embryonic fibroblast (MEF) wound-healing assay with CLASP2 knockout, GFP-CLASP2 fluorescence imaging (FRAP), RNAi knockdown of ACF7 in HeLa cells\",\n      \"journal\": \"Current biology : CB\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — knockout MEFs with defined phenotype, epistasis placing ACF7 upstream, live imaging, replicated across methods\",\n      \"pmids\": [\"17113391\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2006,\n      \"finding\": \"CLASP2 localizes to kinetochores, centrosomes, and the spindle throughout mitosis with fast microtubule-independent turnover. Loss of CLASP2 in primary fibroblasts causes spindle and chromosome segregation defects, slower chromosome movement during anaphase A and B, and severe chromosomal instability, which can be partially rescued by ectopic CLASP1 or CLASP2 expression.\",\n      \"method\": \"Clasp2 knockout mouse fibroblasts, ectopic rescue expression, live-cell imaging, FRAP\",\n      \"journal\": \"Molecular biology of the cell\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — genetic knockout with rescue, multiple mitotic phenotypes quantified, FRAP for turnover, replicated\",\n      \"pmids\": [\"16914514\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2007,\n      \"finding\": \"CLASP2α co-localizes with stress fibers and co-immunoprecipitates with actin. Both the microtubule-binding domain and the N-terminal TOG domain of CLASP2α possess actin-binding activity. FRET experiments confirm proximity between YFP-CLASP2α and CFP-actin, establishing CLASPs as actin/microtubule crosslinkers.\",\n      \"method\": \"Co-immunoprecipitation, deletion mapping, FRET (YFP/CFP), retrograde flow imaging in Xenopus fibroblasts and neurons\",\n      \"journal\": \"Cell motility and the cytoskeleton\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — co-IP, FRET, domain mapping, single lab with multiple orthogonal methods\",\n      \"pmids\": [\"17342765\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2009,\n      \"finding\": \"GSK-3β directly phosphorylates CLASP2 at Ser533 and Ser537, causing dissociation of CLASP2 from IQGAP1, EB1, and microtubules. IQGAP1 was identified as a novel CLASP2-binding protein. Expression of active GSK-3β abolishes CLASP2 distribution on microtubules at leading edges, but a nonphosphorylatable CLASP2 mutant resists this effect.\",\n      \"method\": \"In vitro phosphorylation assay, co-immunoprecipitation, site-directed mutagenesis, confocal imaging in migrating fibroblasts\",\n      \"journal\": \"Journal of cell science\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 / Strong — direct in vitro phosphorylation, mutagenesis (non-phosphorylatable mutant), co-IP, loss-of-function phenotype with multiple orthogonal methods\",\n      \"pmids\": [\"19638411\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"During mitosis, CLASP2 is phosphorylated by Cdk1 at S1234, which primes it for Plk1 association and enhances Plk1 recruitment to kinetochores. Plk1 then phosphorylates CLASP2 C-terminal sites, stabilizing kinetochore-MT attachments required for chromosome alignment and spindle bipolarity, and enabling timely SAC satisfaction.\",\n      \"method\": \"Phospho-site mutagenesis, kinase assays, live-cell imaging, dominant-negative and phosphomimetic constructs\",\n      \"journal\": \"The Journal of cell biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 / Strong — in vitro kinase assays, mutagenesis of phospho-sites, rescue experiments, multiple functional readouts\",\n      \"pmids\": [\"23045552\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"Multisite GSK3 phosphorylation of CLASP2 near its two SXIP EB1-binding motifs disrupts arginine-glutamate salt bridge (electrostatic 'molecular Velcro') interactions required for EB1 binding. Priming phosphorylation by CDKs is required before GSK3 can act; this multisite phosphorylation completely abolishes CLASP2 microtubule plus-end tracking in mitosis.\",\n      \"method\": \"In vitro binding assays, molecular dynamics simulations, 31P NMR spectroscopy, phosphomimetic mutagenesis, live-cell tracking\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — in vitro reconstitution, NMR, MD simulations, mutagenesis, and live-cell validation, multiple orthogonal methods in one study\",\n      \"pmids\": [\"22467876\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"Agrin activates PI3K and inactivates GSK3β locally, leading to CLASP2-mediated capture of dynamic microtubule plus-ends at acetylcholine receptor (AChR) clusters at the neuromuscular junction. Loss of CLASP2 reduces microtubule plus-end density at the synaptic membrane, AChR density, cluster size, and subsynaptic gene expression programs.\",\n      \"method\": \"RNAi knockdown of CLASP2 in myotubes, pharmacological PI3K/GSK3β manipulation, live and fixed imaging\",\n      \"journal\": \"The Journal of cell biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — RNAi with defined cellular phenotypes, pharmacological pathway manipulation, multiple readouts linking pathway to CLASP2 function\",\n      \"pmids\": [\"22851317\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"CLASP2 knockdown in primary mouse neurons decreases axon and dendritic length, while overexpression causes multiple axon formation, enhanced dendritic branching, Golgi condensation, and increased excitatory synapse number and synaptic transmission, identifying CLASP2 as a regulator of neuronal polarity and synapse formation.\",\n      \"method\": \"shRNA knockdown and overexpression in primary mouse neurons, confocal imaging, electrophysiology (miniature events), immunostaining\",\n      \"journal\": \"The Journal of neuroscience\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — bidirectional manipulation (KD and OE) with defined morphological and electrophysiological phenotypes, multiple readouts\",\n      \"pmids\": [\"23035100\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"CLASP2 undergoes insulin-stimulated phosphorylation and co-localizes with GLUT4 at the plasma membrane in areas of cortical actin remodeling. CLASP2 siRNA knockdown in L6 myotubes impairs insulin-stimulated GLUT4 localization to the plasma membrane, and CLASP2 knockdown in 3T3-L1 adipocytes inhibits insulin-stimulated glucose transport.\",\n      \"method\": \"Mass spectrometry, phosphoantibody immunoprecipitation, confocal imaging, siRNA knockdown, glucose transport assay\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — siRNA KD with functional glucose transport readout and imaging, single lab, multiple cell types\",\n      \"pmids\": [\"22992739\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"CLASP2 directly interacts with p120-catenin and localizes to adherens junctions in primary basal keratinocytes. Reduction in p120 or CLASP2 levels decreases localization of the other protein to cell-cell contacts, alters junction dynamics/stability, and reduces MT density and dynamics at intercellular junctions.\",\n      \"method\": \"Co-immunoprecipitation (direct interaction), siRNA knockdown, confocal imaging, live-cell MT dynamics analysis\",\n      \"journal\": \"The Journal of cell biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — co-IP for direct interaction, RNAi with phenotypic readout, single lab with multiple methods\",\n      \"pmids\": [\"24368809\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"Protein 4.1R interacts and co-localizes with cortical CLASP2 and is required for correct number and dynamics of CLASP2 cortical platforms. 4.1R controls CLASP2 binding to MTs at the cell edge by locally altering GSK3 activity. Loss of 4.1R causes MT plus-ends to continue growing and bending rather than being tethered to the cortex.\",\n      \"method\": \"Co-immunoprecipitation, siRNA knockdown, confocal live imaging, GSK3 activity assays\",\n      \"journal\": \"Journal of cell science\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — co-IP, RNAi, live imaging, GSK3 activity measurement, single lab\",\n      \"pmids\": [\"23943871\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"Abl tyrosine kinase binds to CLASP2 and phosphorylates it (Km ~1.89 µM) in response to serum or PDGF stimulation. Abl-phosphorylated tyrosine residues map within F-actin and MT plus-end interaction domains. Abl phosphorylation of CLASP2 modulates its direct binding to MTs and actin, and alters its localization and F-actin distribution in spinal cord growth cones.\",\n      \"method\": \"In vitro kinase assay with purified proteins, mass spectrometry phosphosite identification, co-immunoprecipitation, pulldown with purified proteins, confocal imaging\",\n      \"journal\": \"Cytoskeleton (Hoboken, N.J.)\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 / Moderate — in vitro kinase reconstitution with Km determination, MS phosphosite mapping, pulldown with purified proteins, cell imaging; single lab\",\n      \"pmids\": [\"24520051\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"PAR3 directly interacts with CLASP2 and aPKC phosphorylates CLASP2. This phosphorylation inhibits the interaction between CLASP2 and GCC185 (a TGN protein). Loss of PAR3 or aPKC causes aberrant accumulation of CLASP2 at the TGN and disrupts Golgi ribbon organization. A CLASP2 mutant blocking PAR3 interaction disrupts Golgi organization.\",\n      \"method\": \"Co-immunoprecipitation, in vitro phosphorylation, dominant-negative mutants, siRNA knockdown, confocal imaging of Golgi\",\n      \"journal\": \"Molecular biology of the cell\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 1-2 / Moderate — direct interaction by co-IP, in vitro phosphorylation, mutagenesis, siRNA; single lab\",\n      \"pmids\": [\"25518939\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"Crystal structures of the two TOG domains of CLASP2 reveal paddle-like tubulin-binding conformations with six HEAT repeats each, but with distinct degrees and directions of curvature. Biochemical and cell biological analyses show each TOG domain associates differently with αβ-tubulin, suggesting they discriminate between different states of MT dynamic instability.\",\n      \"method\": \"X-ray crystallography, biochemical binding assays, molecular modeling, cell biology analysis\",\n      \"journal\": \"Journal of molecular biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — crystal structures with functional biochemical validation, multiple methods; single lab\",\n      \"pmids\": [\"26003921\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"CLASP2-mediated microtubule capture at NMJ AChR clusters requires the CLASP2-binding partner LL5β. Forced expression of a CLASP2 fragment blocking CLASP2/LL5β interaction inhibits MT capture and impairs focal vesicle delivery to clusters. LL5β knockdown at the NMJ in vivo reduces AChR density and insertion. MT and actin depolymerization also inhibit MT capture and focal vesicle delivery.\",\n      \"method\": \"RNAi knockdown of LL5β, dominant-negative CLASP2 fragment expression, live imaging of vesicle delivery, in vivo NMJ analysis\",\n      \"journal\": \"Molecular biology of the cell\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — domain-specific inhibition, RNAi, in vivo and in vitro readouts; single lab\",\n      \"pmids\": [\"25589673\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"GSK3-mediated global phosphorylation of CLASP2α largely abolishes its microtubule association in metaphase but does not directly control its kinetochore localization. Phosphorylation-site mutants reveal that CLASP2α phosphorylation weakens kinetochore-MT interactions (reduced sister kinetochore tension) and increases chromosome segregation defects. A model is proposed where only kinetochore-bound CLASP2α is locally dephosphorylated to engage microtubule binding.\",\n      \"method\": \"Dominant phosphorylation-site variants (phosphomimetic and phospho-resistant), live-cell imaging, sister kinetochore tension measurements\",\n      \"journal\": \"Journal of cell science\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — phospho-site mutagenesis with defined mitotic phenotypes, single lab\",\n      \"pmids\": [\"28232523\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"CLASP2 is a cytoskeletal effector in the Reelin signaling pathway. Reelin regulates phosphorylation of GSK3β consensus sites within the CLASP2 serine/arginine-rich region. CLASP2 phosphorylation status regulates its interaction with the Reelin adaptor Dab1, and this association is required for CLASP2 effects on neurite extension and motility during neocortical neuron migration.\",\n      \"method\": \"Co-immunoprecipitation, phosphorylation site mutagenesis, in utero electroporation knockdown, confocal imaging, neuron migration assays\",\n      \"journal\": \"Neuron\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — co-IP for Dab1 interaction, phospho-site mutagenesis, in vivo knockdown with migration phenotype, multiple methods\",\n      \"pmids\": [\"28285824\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"CLASP2 co-immunoprecipitates with SOGA1, MARK2, and G2L1 in 3T3-L1 adipocytes. Reciprocal co-IP confirmed CLASP2-MARK2 and CLASP2-SOGA1 interactions. SOGA1 co-localizes with CLASP2 and tubulin, identifying SOGA1 as a new microtubule-associated protein.\",\n      \"method\": \"Affinity purification-mass spectrometry (AP-MS), reciprocal co-immunoprecipitation, confocal co-localization\",\n      \"journal\": \"Molecular & cellular proteomics : MCP\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — AP-MS with reciprocal co-IP validation, single lab\",\n      \"pmids\": [\"28550165\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"Purified human CLASP2 suppresses microtubule catastrophe and promotes rescue in vitro without affecting growth or shrinkage rates. Combined with EB1, CLASP2 effects are strongly enhanced in a manner dependent on direct CLASP2-EB1 interaction. EB1 targets CLASP2 to microtubules and increases its dwell time at microtubule tips.\",\n      \"method\": \"In vitro reconstitution with purified proteins, TIRF microscopy, truncated EB1 lacking CLASP2-binding domain as control\",\n      \"journal\": \"Molecular biology of the cell\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — in vitro reconstitution with purified proteins, TIRF microscopy, domain-specific controls; rigorous biochemical study\",\n      \"pmids\": [\"29540526\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"Human CLASP2 exists predominantly as a monomer in solution but can self-associate through its C-terminal kinetochore-binding domain. Kinetochore localization is independent of self-association. CLASP2 kinetochore localization, EB-protein interaction (for growing plus-end recognition), and association with curved microtubule protofilaments via TOG2 and TOG3 domains are each independently required for normal kinetochore-MT dynamics, spindle length, SAC satisfaction, and chromosome segregation.\",\n      \"method\": \"In vitro biophysical assays, domain mutant rescue experiments, kinetochore-MT half-life measurements, poleward flux measurements, FRAP\",\n      \"journal\": \"The Journal of cell biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 / Strong — domain dissection with rescue experiments, multiple independent functional readouts, quantitative biophysics; rigorous study\",\n      \"pmids\": [\"31757788\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"CLASP2 is required for HIV-1 to induce microtubule stabilization and promote early infection in human microglia cells. CLASP2 binds to intact HIV-1 cores and in vitro-assembled capsid-nucleocapsid (CA-NC) complexes. The C-terminal domain of CLASP2 (which mediates host effector interactions) is specifically required for MT stabilization and early HIV-1 infection, but not for binding to HIV-1 cores.\",\n      \"method\": \"RNAi knockdown, fixed and live-cell imaging of HIV-1 particle trafficking, in vitro binding to assembled CA-NC complexes, C-terminal domain deletion mutant\",\n      \"journal\": \"Journal of virology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — direct binding assay to CA-NC complexes, domain mutant, RNAi with infection phenotype; single lab\",\n      \"pmids\": [\"32376623\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"The combination of CLASP2 with EB1, XMAP215, and MCAK reconstitutes robust plus-end-leading microtubule treadmilling in vitro. CLASP2's catastrophe suppression and rescue promotion contribute to the dynamic balance enabling treadmilling.\",\n      \"method\": \"In vitro reconstitution with purified proteins (multi-MAP assay), TIRF microscopy, computational simulations\",\n      \"journal\": \"Proceedings of the National Academy of Sciences\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — in vitro reconstitution with purified proteins, computational prediction confirmed experimentally, multiple orthogonal approaches\",\n      \"pmids\": [\"32457163\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"SOCS3 interacts with CLASP2 and CLIP-170 via its N-terminal domain, forming a complex. This SOCS3-CLIP-170/CLASP2 complex is essential for maximal SOCS3 anti-inflammatory effects in lung endothelial cells. IL-6 and HKSA disrupt SOCS3 interaction with CLASP2/CLIP-170. CLASP2 knockdown impairs SOCS3-JAK2 interaction and abolishes anti-inflammatory effects of SOCS3.\",\n      \"method\": \"Co-immunoprecipitation, RNAi knockdown, MT fractionation, endothelial barrier assays, EC-specific SOCS3 KO mice\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — co-IP for interaction, RNAi with functional phenotypes, in vivo KO model; single lab\",\n      \"pmids\": [\"33372035\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"LRAP35a promotes CLASP2/EB1 interaction for MT stabilization. Sequential phosphorylation of LRAP35a by PKA then GSK3β initiates LRAP35a-CLASP2 association. Subsequent CK1δ phosphorylation of CLASP2 (on GSK3β sites that block EB1 SxIP binding) is directly countered by LRAP35a interaction competing for CK1δ activity, thus regulating MT dynamics during cell migration.\",\n      \"method\": \"Co-immunoprecipitation, phospho-site mutagenesis, kinase inhibition, live-cell MT dynamics imaging\",\n      \"journal\": \"Cell reports\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — co-IP, mutagenesis, pharmacological kinase manipulation; single lab with multiple methods\",\n      \"pmids\": [\"34525355\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"CLASP2α directly cross-links F-actin to the microtubule lattice in vitro. A minimal construct L-TOG2-S (containing TOG2 domain and serine-arginine-rich region) retains this cross-linking ability. CLASP2α promotes accumulation of multiple actin filaments along a single microtubule, and depletion of CLASPs in vascular smooth muscle cells causes disorganized actin fibers and reduced co-alignment with microtubules.\",\n      \"method\": \"In vitro reconstitution with purified proteins, TIRF microscopy, CLASP2 depletion in VSMCs, confocal imaging\",\n      \"journal\": \"Molecular biology of the cell\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 / Strong — in vitro reconstitution with purified proteins, domain dissection (minimal construct), cellular KD with phenotypic readout; multiple methods\",\n      \"pmids\": [\"36598814\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"CLASP2 forms a load-bearing bond with terminal non-GTP tubulins at stabilized microtubule tips using its TOG2 domain. TOG2 releases its high-affinity bond upon conversion of non-GTP dimers to polymerization-competent GTP-tubulins. This nucleotide-state-sensitive recognition of curved protofilaments suppresses catastrophe and promotes persistent tubulin assembly at load-bearing (e.g., kinetochore) ends.\",\n      \"method\": \"DNA origami-based reconstruction assays, in vitro biochemical assays, nucleotide exchange experiments, force measurement\",\n      \"journal\": \"Science advances\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — DNA origami reconstitution with load-bearing measurements, domain-specific (TOG2) functional dissection, nucleotide-state specificity demonstrated biochemically; rigorous study\",\n      \"pmids\": [\"36598991\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2009,\n      \"finding\": \"FEZ1 and CLASP2 interact through coiled-coil regions in vitro, co-localize with NEK1 in a perinuclear/centrosomal region, and all three interact with endogenous gamma-tubulin. CLASP2 is phosphorylated by and interacts with active PKC isoforms; PMA treatment inhibits FEZ1/CLASP2 co-localization.\",\n      \"method\": \"Co-immunoprecipitation, in vitro coiled-coil interaction assay, immunofluorescence co-localization, PMA treatment\",\n      \"journal\": \"Molecular and cellular biochemistry\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — single co-IP/pulldown, co-localization only, single lab with limited mechanistic follow-up\",\n      \"pmids\": [\"19924516\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"GSK3β phosphorylation of CLASP2 regulates AChR cluster size at the NMJ: a nonphosphorylatable CLASP2 mutant (9XS/9XA) promotes MT capture and increases AChR cluster size, while a phosphomimetic mutant (8XS/D) reduces MT capture and AChR cluster size despite enrichment at clusters.\",\n      \"method\": \"Expression of phosphomimetic and phospho-resistant CLASP2 mutants in myotubes on agrin patches, live MT imaging, quantitative AChR cluster analysis\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — bidirectional mutagenesis (phosphomimetic vs phospho-resistant) with functional MT capture and receptor density readouts; single lab\",\n      \"pmids\": [\"25231989\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"CLASP2 directly interacts with IQGAP1 to regulate F-actin cytoskeleton remodeling in bladder cancer cells. TNF-α promotes METTL3-mediated m6A modification of CLASP2 mRNA, enhancing its stability and increasing CLASP2 protein levels, which drives CLASP2-IQGAP1-dependent F-actin reorganization and metastasis.\",\n      \"method\": \"Co-immunoprecipitation (Co-IP), MeRIP for m6A detection, immunofluorescence, siRNA knockdown, xenograft mouse model\",\n      \"journal\": \"Biochimica et biophysica acta. Molecular basis of disease\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2-3 / Moderate — co-IP for CLASP2-IQGAP1 interaction, MeRIP for m6A, RNAi with functional readouts; single lab\",\n      \"pmids\": [\"40118293\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"CLASP2 is a microtubule plus-end tracking protein that suppresses catastrophe and promotes rescue by binding non-GTP tubulins at curved protofilament tips via its TOG2 domain, tracks growing MT ends through direct EB1 interaction (via SXIP motifs), and cross-links F-actin to the MT lattice via its TOG2 and serine-arginine-rich region; its activity is spatiotemporally controlled by multisite phosphorylation from GSK3β (disrupting EB1/IQGAP1/MT binding), Cdk1/Plk1 (regulating kinetochore-MT attachment stability during mitosis), aPKC (controlling Golgi organization via GCC185 interaction), and Abl (modulating actin/MT binding at growth cones), while at the cell cortex CLASP2 captures MT plus-ends through LL5β and protein 4.1R to direct GLUT4 vesicle delivery, acetylcholine receptor insertion at the NMJ, and directional cell migration.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"CLASP2 is a microtubule plus-end tracking protein that stabilizes microtubules by suppressing catastrophe and promoting rescue, and that cross-links the actin and microtubule cytoskeletons to organize polarized cell behaviors [#19, #25]. Purified CLASP2 intrinsically suppresses catastrophe and promotes rescue without altering growth or shrinkage rates, and its activity is targeted and amplified by direct binding to EB1, which delivers CLASP2 to and prolongs its dwell at growing plus-ends [#19]; together with EB1, XMAP215, and MCAK it reconstitutes plus-end-leading microtubule treadmilling in vitro [#22]. Mechanistically, its tandem TOG domains adopt distinct curved tubulin-binding conformations that discriminate states of dynamic instability, and the TOG2 domain forms a load-bearing, nucleotide-state-sensitive bond with terminal non-GTP tubulins at curved protofilament tips, releasing upon conversion to GTP-tubulin to enable persistent assembly at load-bearing ends [#14, #26]. CLASP2 cross-links F-actin to the microtubule lattice through a minimal TOG2 plus serine-arginine-rich module [#25]. This activity is gated by multisite phosphorylation: GSK3\\u03b2 phosphorylation near the SXIP EB1-binding motifs disrupts the salt-bridge interactions required for EB1 binding and abolishes plus-end tracking, with CDK priming required beforehand [#6, #4], while Cdk1 priming and Plk1 act during mitosis to stabilize kinetochore-microtubule attachments [#5]. At kinetochores, centrosomes, and the spindle, CLASP2 is required for chromosome segregation and spindle integrity, with kinetochore localization, EB-protein binding, and TOG-mediated recognition of curved protofilaments each independently necessary for normal kinetochore-MT dynamics [#2, #20]. At the cell cortex, CLASP2 captures and tethers microtubule plus-ends through partners including LL5\\u03b2 and protein 4.1R to direct focal vesicle delivery and AChR insertion at the neuromuscular junction and insulin-stimulated GLUT4 delivery, and it drives persistent directional migration via cortical localization controlled by ACF7 [#15, #11, #9, #1]. CLASP2 additionally functions as a cytoskeletal effector in Reelin/Dab1 signaling during neocortical neuron migration and regulates neuronal polarity and synapse formation [#17, #8].\",\n  \"teleology\": [\n    {\n      \"year\": 2005,\n      \"claim\": \"Established how CLASP2 stabilizes microtubules: by directly binding EB1 and tethering microtubules to the cell cortex, confining dynamics to the cell periphery.\",\n      \"evidence\": \"RNAi, direct binding assays, domain deletion, and live imaging in HeLa cells\",\n      \"pmids\": [\"15631994\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Identity of the cortical anchor undefined at this stage\", \"No in vitro reconstitution of stabilization activity\"]\n    },\n    {\n      \"year\": 2006,\n      \"claim\": \"Defined CLASP2's cellular roles in polarized motility and in mitosis, placing ACF7 upstream of its cortical localization and demonstrating segregation/spindle requirements.\",\n      \"evidence\": \"CLASP2 knockout MEFs in wound-healing and mitotic assays, FRAP, ACF7 RNAi\",\n      \"pmids\": [\"17113391\", \"16914514\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Molecular link between ACF7 and CLASP2 cortical capture unresolved\", \"Kinetochore recruitment mechanism unknown\"]\n    },\n    {\n      \"year\": 2007,\n      \"claim\": \"Showed CLASP2 is an actin/microtubule crosslinker, mapping actin-binding to its MT-binding and N-terminal TOG domains.\",\n      \"evidence\": \"Co-IP, deletion mapping, and FRET in Xenopus fibroblasts/neurons\",\n      \"pmids\": [\"17342765\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Crosslinking not reconstituted with purified proteins\", \"Functional consequence of actin binding not established\"]\n    },\n    {\n      \"year\": 2009,\n      \"claim\": \"Identified GSK3\\u03b2 as a direct regulator that switches off CLASP2 by phosphorylating Ser533/Ser537 to dissociate it from EB1, IQGAP1, and microtubules, establishing phospho-gating of plus-end tracking.\",\n      \"evidence\": \"In vitro phosphorylation, mutagenesis, co-IP, imaging in migrating fibroblasts\",\n      \"pmids\": [\"19638411\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Phosphatase that reverses the mark unidentified\", \"Spatial control of GSK3\\u03b2 activity not defined\"]\n    },\n    {\n      \"year\": 2012,\n      \"claim\": \"Resolved the structural logic of phospho-control and extended it to mitosis: GSK3 multisite phosphorylation disrupts SXIP salt-bridge contacts (with CDK priming) and Cdk1/Plk1 cascades stabilize kinetochore-MT attachments.\",\n      \"evidence\": \"In vitro binding, 31P NMR, MD simulations, phospho-site mutagenesis, kinase assays, live imaging\",\n      \"pmids\": [\"22467876\", \"23045552\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"How local dephosphorylation is achieved at specific sites unclear\", \"Integration of multiple kinase inputs in vivo not fully mapped\"]\n    },\n    {\n      \"year\": 2012,\n      \"claim\": \"Connected CLASP2 to physiological cortical capture: agrin/PI3K/GSK3\\u03b2 signaling licenses CLASP2 to capture plus-ends at AChR clusters, and CLASP2 controls neuronal polarity and synapse formation.\",\n      \"evidence\": \"RNAi/overexpression in myotubes and neurons, pharmacological pathway manipulation, electrophysiology, imaging\",\n      \"pmids\": [\"22851317\", \"23035100\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Cortical receptor linking CLASP2 to AChR clusters not yet identified here\", \"Mechanism coupling capture to subsynaptic gene expression unknown\"]\n    },\n    {\n      \"year\": 2012,\n      \"claim\": \"Linked CLASP2 to metabolic vesicle delivery, showing insulin-stimulated phosphorylation and a requirement for insulin-stimulated GLUT4 delivery and glucose transport.\",\n      \"evidence\": \"Mass spectrometry, phosphoantibody IP, siRNA, glucose transport assay in myotubes/adipocytes\",\n      \"pmids\": [\"22992739\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Insulin-responsive kinase site not defined\", \"Direct role at GLUT4 vesicle docking versus indirect not separated\"]\n    },\n    {\n      \"year\": 2013,\n      \"claim\": \"Identified cortical/junctional partners (p120-catenin, protein 4.1R) that recruit CLASP2 and locally tune GSK3 to govern microtubule tethering at the cell edge and adherens junctions.\",\n      \"evidence\": \"Co-IP, siRNA, live MT dynamics imaging, GSK3 activity assays\",\n      \"pmids\": [\"24368809\", \"23943871\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Whether 4.1R/p120 interactions are direct or scaffolded not fully resolved\", \"Mechanism of local GSK3 regulation by 4.1R unclear\"]\n    },\n    {\n      \"year\": 2014,\n      \"claim\": \"Expanded the kinase repertoire and structural basis: Abl phosphorylates CLASP2 within actin/MT-binding domains to modulate growth-cone cytoskeleton, aPKC/PAR3 control Golgi organization via GCC185, and TOG crystal structures reveal distinct tubulin-binding curvatures.\",\n      \"evidence\": \"In vitro kinase assays, MS phosphosite mapping, co-IP, X-ray crystallography, mutagenesis\",\n      \"pmids\": [\"24520051\", \"25518939\", \"26003921\", \"25231989\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"How distinct TOG conformations map to specific dynamic-instability states not directly demonstrated in cells\", \"Crosstalk among Abl/aPKC/GSK3 inputs unresolved\"]\n    },\n    {\n      \"year\": 2015,\n      \"claim\": \"Established LL5\\u03b2 as the cortical partner required for CLASP2-mediated MT capture and focal vesicle delivery at the NMJ.\",\n      \"evidence\": \"LL5\\u03b2 RNAi, dominant-negative CLASP2 fragment, live vesicle imaging, in vivo NMJ analysis\",\n      \"pmids\": [\"25589673\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Whether CLASP2-LL5\\u03b2 binding is direct not established here\", \"Cargo specificity of focal delivery undefined\"]\n    },\n    {\n      \"year\": 2017,\n      \"claim\": \"Demonstrated CLASP2 acts as a cytoskeletal effector in Reelin signaling via phospho-regulated Dab1 association, and refined the kinetochore phospho-model where only kinetochore-bound CLASP2 is locally dephosphorylated.\",\n      \"evidence\": \"Co-IP, phospho-site mutagenesis, in utero electroporation, migration assays, kinetochore tension measurements\",\n      \"pmids\": [\"28285824\", \"28232523\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Phosphatase mediating local kinetochore dephosphorylation unidentified\", \"Direct Dab1-CLASP2 contact interface not mapped\"]\n    },\n    {\n      \"year\": 2018,\n      \"claim\": \"Reconstituted CLASP2's intrinsic activity, proving it suppresses catastrophe and promotes rescue and that EB1 targets it to and prolongs its dwell at MT tips through direct interaction.\",\n      \"evidence\": \"In vitro reconstitution with purified proteins, TIRF microscopy, EB1 truncation controls\",\n      \"pmids\": [\"29540526\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Stoichiometry of the CLASP2-EB1-MT complex not defined\", \"Which TOG domain mediates rescue not resolved here\"]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"Dissected CLASP2's molecular determinants in mitosis (independent requirements for kinetochore localization, EB binding, and TOG2/TOG3 protofilament recognition), defined treadmilling reconstitution, and uncovered roles in HIV-1 infection.\",\n      \"evidence\": \"Domain-mutant rescue, biophysics, FRAP; multi-MAP in vitro reconstitution; HIV-1 binding and infection assays\",\n      \"pmids\": [\"31757788\", \"32457163\", \"32376623\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"How the three activities are coordinated temporally at kinetochores unclear\", \"Functional consequence of C-terminal self-association unknown\"]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"Defined the biophysical mechanism of stabilization: TOG2 forms a load-bearing, nucleotide-state-sensitive bond with terminal non-GTP tubulins at curved protofilaments, and reconstituted actin-MT crosslinking via a minimal TOG2/SR module.\",\n      \"evidence\": \"DNA origami reconstitution with force measurement, nucleotide exchange, in vitro crosslinking, VSMC depletion\",\n      \"pmids\": [\"36598991\", \"36598814\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"How load-bearing tip binding is integrated with EB1-mediated tip tracking unresolved\", \"In vivo contribution of crosslinking to specific tissues limited\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Extended CLASP2 regulation to RNA-level control and disease, showing TNF-\\u03b1/METTL3 m6A stabilization of CLASP2 mRNA driving CLASP2-IQGAP1-dependent actin remodeling and metastasis.\",\n      \"evidence\": \"Co-IP, MeRIP, siRNA, xenograft model in bladder cancer cells\",\n      \"pmids\": [\"40118293\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct versus scaffolded CLASP2-IQGAP1 interaction in this context not separated\", \"Causal contribution of m6A site to phenotype not isolated\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How CLASP2's distinct activities — intrinsic tip stabilization, EB-mediated tracking, actin crosslinking, and cortical capture — are integrated and switched by competing phospho-inputs in a single cell remains unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No unified model coupling kinase inputs to spatial activity states\", \"Phosphatases reversing GSK3/Cdk1/Plk1 marks largely unidentified\", \"Quantitative hierarchy of cortical partners in different tissues undefined\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0008092\", \"supporting_discovery_ids\": [3, 19, 22, 25, 26]},\n      {\"term_id\": \"GO:0060090\", \"supporting_discovery_ids\": [0, 11, 15, 25]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005856\", \"supporting_discovery_ids\": [0, 19, 25]},\n      {\"term_id\": \"GO:0005886\", \"supporting_discovery_ids\": [0, 9, 15]},\n      {\"term_id\": \"GO:0005815\", \"supporting_discovery_ids\": [2, 27]},\n      {\"term_id\": \"GO:0005794\", \"supporting_discovery_ids\": [13]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-1640170\", \"supporting_discovery_ids\": [2, 5, 16, 20]},\n      {\"term_id\": \"R-HSA-9609507\", \"supporting_discovery_ids\": [9, 15]},\n      {\"term_id\": \"R-HSA-162582\", \"supporting_discovery_ids\": [7, 17, 23]},\n      {\"term_id\": \"R-HSA-1266738\", \"supporting_discovery_ids\": [8, 17]}\n    ],\n    \"complexes\": [\"kinetochore\"],\n    \"partners\": [\"EB1\", \"IQGAP1\", \"LL5B\", \"EPB41\", \"PARD3\", \"DAB1\", \"CLIP1\", \"MARK2\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":8,"faith_total":8,"faith_pct":100.0}}