{"gene":"NCK2","run_date":"2026-06-10T05:19:52","timeline":{"discoveries":[{"year":1998,"finding":"NCK2 (Nck-2) was identified as an adaptor protein comprising three N-terminal SH3 domains and one C-terminal SH2 domain. It interacts with PINCH via the fourth LIM domain of PINCH and the third SH3 domain of NCK2. NCK2 also binds EGF receptor (largely via its SH2 domain, with SH3 domains contributing), PDGF receptor-β (solely via SH2 domain, PDGF-dependent), and IRS-1 (primarily via second and third SH3 domains). A fraction of NCK2 was found associated with the cytoskeleton.","method":"Yeast two-hybrid, Co-IP, GST pulldown, domain mutagenesis","journal":"Molecular biology of the cell","confidence":"High","confidence_rationale":"Tier 1-2 / Strong — multiple orthogonal methods (yeast two-hybrid, Co-IP, pulldown, mutagenesis) in a single foundational paper establishing domain-specific interactions","pmids":["9843575"],"is_preprint":false},{"year":2000,"finding":"NCK2 (Nckbeta) plays a specific role in PDGF-BB-induced actin polymerization. Overexpression of NCK2 but not NCK1 blocks PDGF-stimulated membrane ruffling and lamellipodia. Mutation in either the SH2 or the middle SH3 domain abolishes this effect. NCK2 binds PDGFR-β at Tyr-1009 (distinct from NCK1's Tyr-751 binding site). Anti-NCK2 but not anti-NCK1 microinjection inhibits PDGF-stimulated actin polymerization. Constitutively membrane-bound NCK2 blocks Rac1-L62-induced membrane ruffling, suggesting NCK2 acts in parallel to or downstream of Rac1.","method":"Overexpression, dominant-negative mutants, microinjection of isoform-specific antibodies, site-directed mutagenesis","journal":"Molecular and cellular biology","confidence":"High","confidence_rationale":"Tier 2 / Strong — multiple orthogonal methods (antibody microinjection, overexpression, mutagenesis, constitutively active constructs) establishing NCK2-specific function","pmids":["11027258"],"is_preprint":false},{"year":1999,"finding":"NCK2 (Grb4) associates with receptor tyrosine kinases and SH3-binding proteins PAK, Sos1, and PRK2. NCK2 synergizes with v-Abl and Sos1 to induce Elk-1-dependent gene expression and cooperates with v-Abl to transform NIH 3T3 cells.","method":"Co-IP, reporter gene assay, transformation assay","journal":"The Journal of biological chemistry","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — Co-IP and functional assays in single lab, multiple readouts","pmids":["10026169"],"is_preprint":false},{"year":2001,"finding":"NCK2 interacts with DOCK180 via its second and third SH3 domains. A major binding site maps to DOCK180 residues 1819–1836 (recognized primarily by the third SH3 domain). Two binding events occur with equilibrium dissociation constants of ~415 nM and ~3.24 nM. Both SH3 domains contribute cooperatively, with tandem SH3 domains greatly enhancing binding compared to individual domains alone.","method":"Yeast two-hybrid, GST pulldown, surface plasmon resonance, site-directed mutagenesis","journal":"FEBS letters","confidence":"High","confidence_rationale":"Tier 1 / Strong — in vitro binding reconstitution with surface plasmon resonance kinetics plus mutagenesis, multiple orthogonal methods","pmids":["11240126"],"is_preprint":false},{"year":2001,"finding":"NCK2 SH3 domains directly interact with IRS-1 in vivo. Multiple SH3 domains (with conserved tryptophan residues critical) enhance complex formation. IRS-1 PTB/SAIN domain and Pre-C-terminal domain (but not PH domain) mediate NCK2 binding. The interaction is direct (occurs in absence of other proteins).","method":"Co-IP, GST pulldown, in vitro binding assay, deletion and point mutagenesis","journal":"The Biochemical journal","confidence":"High","confidence_rationale":"Tier 1 / Moderate — direct in vitro binding reconstitution plus mutagenesis of both partners, single lab but rigorous","pmids":["11171109"],"is_preprint":false},{"year":2002,"finding":"NCK2 interacts with focal adhesion kinase (FAK) through multiple SH2 and SH3 domains. The SH2-mediated interaction requires phosphorylation of FAK Tyr397. A fraction of NCK2 co-localizes with FAK at the cell periphery in spreading cells. Overexpression of NCK2 modestly decreases cell motility, whereas a SH2-only NCK2 mutant lacking SH3 domains significantly promotes motility.","method":"Co-IP, mutagenesis, immunofluorescence co-localization, overexpression motility assay","journal":"The international journal of biochemistry & cell biology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — Co-IP with mutagenesis plus localization and functional assay, single lab","pmids":["11950595"],"is_preprint":false},{"year":2002,"finding":"BDNF stimulation promotes interaction of NCK2 with the TrkB tyrosine kinase receptor. Tyrosines Y694, Y695, and Y771 in the TrkB intracellular domain are crucial for this interaction. NCK2 was co-precipitated with GST-NCK2 recombinant protein or anti-Nck antibody from BDNF-activated cortical neurons.","method":"Yeast two-hybrid, GST pulldown, Co-IP from cortical neurons, mutagenesis","journal":"Biochemical and biophysical research communications","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — yeast two-hybrid plus GST pulldown and Co-IP from neurons, single lab","pmids":["12074588"],"is_preprint":false},{"year":2001,"finding":"NCK2 (Grb4) acts as a nuclear repressor of v-Abl-induced transcriptional activation from AP-1 and SRE promoter elements. This inhibitory activity is independent of direct v-Abl/NCK2 SH2 interaction; a SH2 domain mutant shows even stronger inhibition. The first two SH3 domains primarily mediate inhibitory function. The inhibitory activity is downstream of MEKK1 and JNK. Cell fractionation and fluorescence microscopy revealed that stronger inhibitory SH2 mutants show increased nuclear localization.","method":"Reporter gene assay, domain mutagenesis, cell fractionation, fluorescence microscopy","journal":"The Journal of biological chemistry","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — functional reporter assay with mutagenesis and subcellular fractionation, single lab","pmids":["11514578"],"is_preprint":false},{"year":2005,"finding":"The NMR solution structure of the human NCK2 SH2 domain was determined. It adopts the core SH2 fold but with a unique C-terminal antiparallel β-sheet not previously identified in other SH2 domains. The NCK2 SH2 domain binds three phosphorylated ephrinB2 fragments ([Tyr(P)304], [Tyr(P)316], and [Tyr(P)330]ephrinB2) via different mechanisms and with distinct conformational dynamics.","method":"NMR structure determination, NMR titration (HSQC), truncation mutagenesis","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1 / Moderate — NMR structure with functional binding validation and mutagenesis, single lab but rigorous","pmids":["15764601"],"is_preprint":false},{"year":2006,"finding":"Crystal structures of NCK1 and NCK2 SH2 domains in complex with phosphopeptides from the EPEC protein Tir established that the SH2 domains of NCK1 and NCK2 have essentially indistinguishable phosphopeptide binding specificities. The second SH3 domain of NCK2 prefers APx#PxR motifs and the third SH3 domain prefers PxAPxR. NCK2 SH3 domains bind GIT1 (Arf-GAP) as experimentally confirmed. High-affinity binding of NCK2 SH3-3 to Nogo-A peptide was identified (Kd = 5.7 μM).","method":"X-ray crystallography, NMR (HSQC titration), isothermal titration calorimetry, binding assays","journal":"The Journal of biological chemistry / Biochemistry","confidence":"High","confidence_rationale":"Tier 1 / Strong — crystal structures plus ITC and NMR binding studies across two papers, replicated findings on binding specificity","pmids":["16636066","16752908"],"is_preprint":false},{"year":2007,"finding":"NCK2 (Nckbeta), but not NCK1, is required for nerve growth factor-induced neurite outgrowth in PC12 cells and for normal axon/dendrite development in primary cortical neurons. NCK2 knockdown reduces steady-state paxillin levels specifically in neurons (not glia). NCK2 binds strongly to paxillin, preventing its proteasomal degradation. Re-expression of non-degradable NCK2 or forced paxillin expression rescues neuritogenesis in NCK2 knockdown cells.","method":"shRNA knockdown, overexpression rescue, Co-IP, proteasome inhibitor treatment, immunoblotting","journal":"Molecular and cellular biology","confidence":"High","confidence_rationale":"Tier 2 / Strong — multiple orthogonal methods (knockdown, rescue, Co-IP, pharmacological inhibition) establishing NCK2-specific mechanism for paxillin stability in neurons","pmids":["17591694"],"is_preprint":false},{"year":2009,"finding":"NCK2 (Nckbeta) and NCK1 (Nckalpha) have non-compensating roles in PDGF-BB-induced dermal fibroblast migration. NCK2 binds PDGFR-β at Tyr-1009 and mediates Rho signaling to induce stress fibers, while NCK1 binds at Tyr-751 and mediates Cdc42 signaling for filopodium formation. Cells from NCK2-knockout mice and NCK2-knockdown human fibroblasts fail to migrate in response to PDGF-BB. The middle SH3 domain of NCK2 alone (dominant negative) blocks PDGF-BB-induced migration.","method":"Knockout MEFs, RNAi knockdown, site-directed mutagenesis of PDGFR-β, dominant-negative SH3 domain overexpression, Rho/Rac/Cdc42 activity assays","journal":"The Journal of investigative dermatology","confidence":"High","confidence_rationale":"Tier 2 / Strong — genetic KO combined with RNAi and receptor mutants plus GTPase activity measurements, multiple orthogonal approaches","pmids":["19242519"],"is_preprint":false},{"year":2010,"finding":"NCK2 is utilized by the integrin adaptor protein Cas (downstream of integrin signaling) to activate Cdc42 and induce cell polarization during wound healing. This is distinct from CrkII (also recruited by Cas) which activates Rac1 to promote cell protrusion extension.","method":"siRNA knockdown, Cdc42/Rac1 activity assays, wound healing assay","journal":"The FEBS journal","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — functional knockdown with GTPase activity assays, single lab","pmids":["20637038"],"is_preprint":false},{"year":2011,"finding":"NCK2 (Nck2) interacts with the SH2 domain of NCK2 via the N-terminus of SKAP2. The SKAP2-NCK2-F-actin complex accumulates at the leading edge of lamellipodia where FGF receptors and focal adhesions are also recruited. NCK2 participates in actin reorganization during lens epithelial cell differentiation.","method":"Co-IP, immunofluorescence co-localization, RNAi knockdown, overexpression with deletion mutants","journal":"Journal of cellular and molecular medicine","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — Co-IP plus co-localization and functional knockdown, single lab","pmids":["20219016"],"is_preprint":false},{"year":2011,"finding":"PAK3 interacts preferentially with NCK2 (over NCK1) in brain extracts and transfected cells, independent of PAK3 kinase activity. Selective uncoupling of NCK2 interactions using an interfering peptide in acute cortical slices causes rapid increase in evoked transmission. The PAK3-P12A mutation strongly reduces binding to NCK2 but only slightly to NCK1. Wild-type PAK3 decreases amplitude of spontaneous miniature excitatory currents, whereas P12A mutant does not, demonstrating that PAK3 down-regulates synaptic transmission through its interaction with NCK2.","method":"Co-IP from brain extracts and transfected cells, interfering peptide, electrophysiology in cortical slices, mutagenesis","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 2 / Strong — Co-IP from native tissue plus interfering peptide plus electrophysiology plus mutagenesis, multiple orthogonal approaches linking NCK2-PAK3 interaction to synaptic function","pmids":["21949127"],"is_preprint":false},{"year":2011,"finding":"NCK2, but not NCK1, is required for Slit1-induced changes in cortical neuron morphology in vitro. NCK1 and NCK2 both bind to the Slit receptor Robo via an atypical SH3-mediated mechanism.","method":"shRNA knockdown (isoform-specific), Co-IP, morphological analysis of cortical neurons, Robo1/Robo2 knockout neurons","journal":"Molecular and cellular neurosciences","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — specific knockdown plus Co-IP identifying mechanism, single lab","pmids":["21600986"],"is_preprint":false},{"year":2013,"finding":"NCK1, but not NCK2, is a substrate of c-Cbl-mediated ubiquitination at Lys178. Synaptopodin competes with c-Cbl for binding to NCK1, preventing NCK1 ubiquitination. Expression of c-Cbl-resistant NCK1(K178R) or NCK2 containing the SH3 domain 2 of NCK1 restores stress fibers in synaptopodin-depleted podocytes through RhoA signaling activation. NCK2 is not ubiquitinated by c-Cbl (negative finding that is mechanistically informative—NCK2 lacks the ubiquitin acceptor site equivalent, explaining its differential regulation).","method":"Ubiquitination assay, mutagenesis (K178R), c-Cbl knockdown, RhoA activity assay, domain-swap constructs","journal":"Nature communications","confidence":"High","confidence_rationale":"Tier 1-2 / Strong — ubiquitination assay with mutagenesis, domain swaps, and RhoA activity measurements establishing differential PTM regulation between NCK1 and NCK2","pmids":["24287595"],"is_preprint":false},{"year":2014,"finding":"In human Jurkat T cells, NCK2 knockdown (to ~10%) reduces TCR-induced NFAT activation but does not significantly impair Erk/MEK phosphorylation, AP-1 activation, or IL-2/CD69 expression (in contrast to NCK1 knockdown). Thus NCK2 has a role in NFAT activation downstream of TCR but not in Erk pathway activation.","method":"shRNA knockdown (isoform-specific), luciferase reporter assays, phospho-immunoblotting","journal":"Cell communication and signaling","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — specific isoform knockdown with multiple signaling readouts, single lab","pmids":["24670066"],"is_preprint":false},{"year":2016,"finding":"NCK2 deficiency in mice promotes adiposity with adipocyte hypertrophy and enhanced adipogenesis. Mechanistically, NCK2 deficiency in adipocyte precursors is associated with primed PERK activation and signaling, which promotes the adipogenic program including enhanced adipocyte differentiation, lipid droplet formation, and dysfunctional lipogenesis/lipolysis.","method":"Knockout mice, in vitro differentiation assays (3T3-L1, stromal vascular fraction), PERK signaling analysis","journal":"Diabetes","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — genetic KO with mechanistic pathway analysis (PERK signaling), single lab","pmids":["27325288"],"is_preprint":false},{"year":2018,"finding":"NCK2 is required for cell abscission during cytokinesis. Nck2-/- (but not Nck1-/-) MEFs are multinucleated, display extended intercellular bridge protrusions, spend extended time in cytokinesis, and fail to complete abscission. The midbody in NCK2-deficient cells is longer and shows mislocalization of AURKB, PLK1, and ECT2. NCK2's SH2 domain is required for its cytokinesis function. AP-MS and BioID identified 28 proteins specifically associated with NCK2 (not NCK1).","method":"Knockout MEFs, AP-MS, BioID proximity labeling, live imaging, immunofluorescence, domain-swap/SH2 mutant rescue","journal":"Molecular & cellular proteomics","confidence":"High","confidence_rationale":"Tier 2 / Strong — genetic KO with live imaging, two interactome methods (AP-MS + BioID), and domain mutagenesis rescue establishing NCK2-specific cytokinesis function","pmids":["30002203"],"is_preprint":false},{"year":2018,"finding":"NCK2 is required for Eph-mediated motor axon trajectory selection in spinal lateral motor column neurons. NCK2 loss- and gain-of-function (via in ovo electroporation) perturbs LMC axon trajectory selection and growth preference against ephrins. NCK2 modulates α2-chimaerin activity in the context of Eph signaling.","method":"In ovo electroporation (loss- and gain-of-function), in vitro neurite growth assay with ephrins, epistasis with α2-chimaerin","journal":"Developmental dynamics","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — in vivo and in vitro loss/gain-of-function with epistasis analysis, single lab","pmids":["30016580"],"is_preprint":false},{"year":2020,"finding":"NCK1 (not NCK2) mediates disturbed flow-induced endothelial permeability and PAK2 activation. Both NCK1 and NCK2 bind PECAM-1 in an SH2-dependent manner in response to shear stress, but only NCK1 ablation interferes with PAK2 membrane translocation and activation. Domain-swap experiments show NCK1 SH3 domains (specifically the first SH3) are critical for PAK recruitment and activation. NCK2 depletion has no significant effect on permeability (negative finding).","method":"Knockout cells, domain-swap constructs, in vivo partial carotid ligation, PAK activity assay, permeability assays (Evans blue, FITC-dextran), single-point SH3 mutations","journal":"Journal of the American Heart Association","confidence":"High","confidence_rationale":"Tier 2 / Strong — in vivo KO model combined with domain swaps and mutagenesis plus in vitro functional readouts, distinguishing NCK1 vs NCK2 roles","pmids":["32468886"],"is_preprint":false},{"year":2022,"finding":"CBL (Casitas B lymphoma E3 ubiquitin ligase) interacts with NCK2, promotes its ubiquitin-mediated proteasomal degradation, and thereby reduces NCK2 protein stability in breast cancer cells. NCK2 overexpression reverses CBL-mediated inhibition of cell proliferation and migration.","method":"Co-IP, IP-mass spectrometry, immunofluorescence co-localization, cycloheximide chase, ubiquitination assay, rescue overexpression","journal":"Nan fang yi ke da xue xue bao","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — multiple Co-IP methods plus ubiquitination assay and rescue experiment, single lab","pmids":["36504051"],"is_preprint":false},{"year":2023,"finding":"OIP5 interacts with NCK2 in human spermatogonial stem cells (SSCs), as demonstrated by Co-IP, IP-MS, and GST pulldown. NCK2 silencing decreases SSC proliferation and DNA synthesis but enhances apoptosis. NCK2 knockdown reverses the influence of OIP5 overexpression on SSC self-renewal.","method":"Co-IP, IP-mass spectrometry, GST pulldown, siRNA knockdown, proliferation and apoptosis assays","journal":"Research (Washington, D.C.)","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — three orthogonal binding methods (Co-IP, IP-MS, GST pulldown) plus functional knockdown, single lab","pmids":["37292517"],"is_preprint":false},{"year":2024,"finding":"NCK2 is associated with EphA4 and RhoA in the olfactory bulb (demonstrated by immunoprecipitation), functioning as a scaffolding protein to modulate EphA4/RhoA pathway. α-synuclein deletion reduces NCK2 levels and EphA4 activation; re-expressing α-synuclein reverses NCK2 downregulation and restores pEphA4 and RhoA activity, improving olfactory neuron projection.","method":"α-synuclein knockout mice, immunoprecipitation, iTRAQ-LC-MS, overexpression rescue","journal":"Cell & bioscience","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — Co-IP plus proteomic identification and genetic rescue in knockout mice, single lab","pmids":["39543759"],"is_preprint":false},{"year":2024,"finding":"KLF4 transcription factor binds directly to the NCK2 promoter and facilitates NCK2 transcription, suppressing antitumor effects of brusatol in melanoma. The miR-150-3p/KLF4/NCK2 axis regulates brusatol's anti-melanoma activity.","method":"ChIP, promoter reporter assay, overexpression and knockdown, Western blot","journal":"Biochemical pharmacology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — ChIP demonstrating direct promoter binding plus functional rescue experiments, single lab","pmids":["38583810"],"is_preprint":false},{"year":2025,"finding":"NCK2 (and NCK1) are enriched within clathrin-coated pits (CCPs) at the plasma membrane and regulate early CCP formation and maturation. NCK2 supports EGF-stimulated Akt phosphorylation. EGF stimulation triggers NCK-dependent enrichment of PI3K within CCPs. Perturbation of NCK adaptors suppresses cell proliferation and survival.","method":"TIRFM (total internal reflection fluorescence microscopy), CCP dynamics analysis, Akt phosphorylation assay, PI3K localization","journal":"bioRxiv","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — live TIRFM imaging with functional signaling readouts, preprint not yet peer-reviewed","pmids":["bio_10.1101_2025.10.24.684344"],"is_preprint":true}],"current_model":"NCK2 is an SH2/SH3 adaptor protein that links activated receptor tyrosine kinases (EGFR, PDGFRβ at Tyr-1009, TrkB) and integrin signaling components (FAK, PINCH, IRS-1, Cas) to cytoplasmic effectors (DOCK180, PAK3, paxillin, Robo, α2-chimaerin) via domain-specific interactions, thereby regulating actin cytoskeleton dynamics, cell migration, neurite outgrowth, synaptic transmission, cytokinesis abscission, and adipogenesis, with its abundance controlled by CBL-mediated ubiquitination (from which NCK2 is less susceptible than NCK1) and KLF4-driven transcription, and its signaling specificity determined by the unique binding preferences of its three SH3 domains and SH2 domain relative to the closely related NCK1 paralog."},"narrative":{"mechanistic_narrative":"NCK2 is a modular SH2/SH3 adaptor protein that couples activated receptor tyrosine kinases and adhesion receptors to actin-regulatory effectors, thereby controlling cytoskeletal dynamics, cell migration, neuronal morphogenesis, and cytokinesis [PMID:9843575, PMID:11027258, PMID:19242519]. Built from three N-terminal SH3 domains and a single C-terminal SH2 domain, it engages receptors through phosphotyrosine-dependent SH2 binding — EGFR, PDGFR-β at Tyr-1009, TrkB, and the integrin scaffold FAK at phospho-Tyr397 — while its tandem SH3 domains recruit downstream effectors including DOCK180, PAK3, IRS-1, paxillin, GIT1, and Robo [PMID:9843575, PMID:11027258, PMID:11240126, PMID:11950595, PMID:12074588, PMID:16636066, PMID:16752908, PMID:21600986]. Its three SH3 modules carry distinct binding preferences (SH3-2 favoring APxxPxR and SH3-3 favoring PxAPxR motifs, with tandem domains binding cooperatively), and although the NCK2 SH2 domain is structurally distinguished by a unique C-terminal antiparallel β-sheet, its phosphopeptide specificity is essentially indistinguishable from NCK1, implying that functional divergence between the paralogs arises largely from SH3-domain selectivity and differential regulation [PMID:11240126, PMID:15764601, PMID:16636066, PMID:16752908]. Through these interactions NCK2 directs specific small-GTPase outputs: it transmits PDGFR-β Tyr-1009 signals to RhoA-driven stress fibers (whereas NCK1 routes Tyr-751 to Cdc42) and is recruited by the integrin adaptor Cas to activate Cdc42 for polarized migration [PMID:19242519, PMID:20637038]. NCK2 has non-redundant, NCK1-independent roles in NGF- and Slit1-induced neurite outgrowth — in part by binding paxillin and protecting it from proteasomal degradation — in PAK3-dependent down-regulation of synaptic transmission, in Eph-mediated motor axon guidance via α2-chimaerin, and in completing cytokinetic abscission, where its SH2 domain is required for proper midbody localization of AURKB, PLK1, and ECT2 [PMID:17591694, PMID:21949127, PMID:21600986, PMID:30002203, PMID:30016580]. NCK2 abundance is set post-translationally by CBL-mediated ubiquitin-proteasomal degradation and transcriptionally by KLF4, and unlike NCK1 it lacks the Lys178 c-Cbl ubiquitination acceptor site, providing a molecular basis for paralog-specific stability [PMID:24287595, PMID:36504051, PMID:38583810].","teleology":[{"year":1998,"claim":"Established NCK2 as a distinct SH2/SH3 adaptor and defined its first domain-specific receptor and scaffold interactions, framing it as a modular signaling linker rather than a redundant NCK1 copy.","evidence":"Yeast two-hybrid, Co-IP, GST pulldown and domain mutagenesis mapping PINCH, EGFR, PDGFR-β and IRS-1 contacts","pmids":["9843575"],"confidence":"High","gaps":["Did not establish functional output of these interactions","Cytoskeletal association observed but mechanism undefined"]},{"year":2000,"claim":"Demonstrated NCK2 has a function not shared by NCK1 in PDGF-induced actin remodeling, providing the first evidence of paralog-specific signaling.","evidence":"Isoform-specific antibody microinjection, overexpression, and SH2/SH3 mutants in fibroblasts, mapping NCK2 to PDGFR-β Tyr-1009","pmids":["11027258"],"confidence":"High","gaps":["Effector linking NCK2 to actin not yet identified","Relationship to Rac1 inferred from epistasis only"]},{"year":2001,"claim":"Resolved how NCK2 SH3 domains achieve high-affinity, cooperative effector binding (DOCK180, IRS-1), explaining how tandem domains generate signaling specificity and avidity.","evidence":"SPR kinetics, GST pulldown, and point mutagenesis of tandem SH3 domains and partner motifs","pmids":["11240126","11171109"],"confidence":"High","gaps":["Cellular consequence of DOCK180 recruitment not tested here","In vivo stoichiometry of cooperative binding unknown"]},{"year":2002,"claim":"Connected NCK2 to focal-adhesion (FAK) and neurotrophin (TrkB) signaling, broadening its receptor repertoire to adhesion and neuronal contexts.","evidence":"Co-IP, phospho-Tyr397-dependent SH2 binding, co-localization and motility assays; BDNF-dependent TrkB Co-IP from cortical neurons","pmids":["11950595","12074588"],"confidence":"Medium","gaps":["Opposing motility effects of full-length vs SH2-only NCK2 not mechanistically resolved","TrkB downstream pathway not defined"]},{"year":2005,"claim":"Provided the structural basis for NCK2 SH2 recognition and revealed a unique fold feature plus multimodal ephrinB2 phosphopeptide binding.","evidence":"NMR solution structure and HSQC titrations with phospho-ephrinB2 fragments","pmids":["15764601"],"confidence":"High","gaps":["Functional role of the unique C-terminal β-sheet untested","ephrinB2-NCK2 cellular signaling not addressed"]},{"year":2006,"claim":"Defined SH3 motif preferences and showed that NCK1 and NCK2 SH2 domains have indistinguishable phosphopeptide specificity, localizing paralog divergence to SH3 domains.","evidence":"X-ray crystallography, ITC, and NMR with Tir, GIT1 and Nogo-A peptides","pmids":["16636066","16752908"],"confidence":"High","gaps":["Does not explain how indistinguishable SH2 domains produce divergent receptor coupling in cells","GIT1/Nogo-A functional roles not tested"]},{"year":2007,"claim":"Identified an NCK2-specific mechanism in neurons: stabilizing paxillin against proteasomal degradation to enable neurite outgrowth, establishing a non-adaptor (protein-stability) role.","evidence":"Isoform-specific shRNA, Co-IP, proteasome inhibition, and non-degradable NCK2/paxillin rescue in PC12 and cortical neurons","pmids":["17591694"],"confidence":"High","gaps":["Molecular basis of NCK2-dependent paxillin protection unclear","Why effect is neuron-specific not explained"]},{"year":2009,"claim":"Showed NCK1 and NCK2 are non-compensating, routing the same receptor to distinct GTPases (NCK2→RhoA/stress fibers at Tyr-1009; NCK1→Cdc42/filopodia at Tyr-751).","evidence":"NCK2-KO MEFs, RNAi, PDGFR-β site mutants, dominant-negative SH3, and GTPase activity assays","pmids":["19242519"],"confidence":"High","gaps":["Intermediate GEF/effector linking NCK2 to RhoA not defined","Generality beyond fibroblasts untested"]},{"year":2010,"claim":"Placed NCK2 downstream of integrin/Cas signaling as a Cdc42 activator for cell polarization, distinguishing it from CrkII-driven Rac1 protrusion.","evidence":"siRNA knockdown, GTPase activity assays, and wound-healing assays","pmids":["20637038"],"confidence":"Medium","gaps":["Direct NCK2-Cas binding mode not mapped here","GEF coupling NCK2 to Cdc42 unknown"]},{"year":2011,"claim":"Extended NCK2-specific functions into neuronal guidance, synaptic transmission, and lamellipodial actin assembly through Robo, PAK3, and SKAP2 partners.","evidence":"Isoform-specific knockdown, Co-IP from brain, interfering peptide plus electrophysiology, and leading-edge co-localization","pmids":["21949127","21600986","20219016"],"confidence":"High","gaps":["Atypical SH3-mediated Robo binding mode not structurally defined","How NCK2-PAK3 down-regulates transmission mechanistically open"]},{"year":2013,"claim":"Explained paralog-specific stability: NCK1 is ubiquitinated by c-Cbl at Lys178 while NCK2 lacks the acceptor site, accounting for differential turnover and signaling persistence.","evidence":"Ubiquitination assays, K178R mutagenesis, domain swaps, and RhoA activity assays in podocytes","pmids":["24287595"],"confidence":"High","gaps":["Whether NCK2 has its own degradation pathway not addressed here","Functional consequence of NCK2 stability in this context not isolated"]},{"year":2014,"claim":"Distinguished NCK2 signaling output in T cells, linking it selectively to TCR-induced NFAT activation rather than the Erk/AP-1 axis used by NCK1.","evidence":"Isoform-specific shRNA, luciferase reporters, and phospho-immunoblotting in Jurkat cells","pmids":["24670066"],"confidence":"Medium","gaps":["Molecular link from NCK2 to NFAT not defined","Direct TCR-proximal partners in this pathway not identified"]},{"year":2016,"claim":"Revealed a metabolic role: NCK2 restrains adipogenesis by suppressing PERK signaling in adipocyte precursors.","evidence":"NCK2-KO mice and in vitro differentiation assays with PERK signaling analysis","pmids":["27325288"],"confidence":"Medium","gaps":["Direct NCK2-PERK molecular link unestablished","Adaptor partners in adipocytes not mapped"]},{"year":2018,"claim":"Defined an NCK1-independent requirement for NCK2 in cytokinetic abscission, with its SH2 domain needed for proper midbody localization of AURKB, PLK1 and ECT2, and an NCK2-specific interactome.","evidence":"NCK2-KO MEFs, live imaging, AP-MS and BioID, and SH2-mutant rescue","pmids":["30002203"],"confidence":"High","gaps":["Direct SH2 ligand at the midbody not identified","Mechanism positioning AURKB/PLK1/ECT2 via NCK2 unresolved"]},{"year":2018,"claim":"Showed NCK2 is required for Eph/ephrin-guided motor axon trajectory selection by modulating α2-chimaerin.","evidence":"In ovo electroporation loss/gain-of-function, ephrin neurite assays, and α2-chimaerin epistasis","pmids":["30016580"],"confidence":"Medium","gaps":["Direct NCK2-α2-chimaerin binding not biochemically mapped","Eph receptor coupling specificity unresolved"]},{"year":2020,"claim":"Sharpened paralog distinction in endothelium: both adaptors bind PECAM-1 under shear, but only NCK1 (via its first SH3) drives PAK2 activation and permeability, with NCK2 dispensable.","evidence":"Knockout cells, domain swaps, single-point SH3 mutants, in vivo carotid ligation, and permeability/PAK assays","pmids":["32468886"],"confidence":"High","gaps":["NCK2's role at PECAM-1, if any, not defined","Why NCK2 SH3 domains fail to recruit PAK here unexplained"]},{"year":2022,"claim":"Identified CBL as an E3 ligase driving NCK2 ubiquitin-proteasomal degradation, controlling NCK2 abundance and its pro-proliferative/migratory output in cancer.","evidence":"Co-IP, IP-MS, cycloheximide chase, ubiquitination assay, and rescue overexpression in breast cancer cells","pmids":["36504051"],"confidence":"Medium","gaps":["NCK2 ubiquitination acceptor site not mapped (contrast with NCK1 Lys178)","Single-lab finding without in vivo validation"]},{"year":2023,"claim":"Linked NCK2 to spermatogonial stem cell self-renewal as an OIP5 effector promoting proliferation and survival.","evidence":"Co-IP, IP-MS, GST pulldown, and siRNA functional assays in human SSCs","pmids":["37292517"],"confidence":"Medium","gaps":["Domain mediating OIP5-NCK2 interaction unmapped","Downstream signaling in SSCs undefined"]},{"year":2024,"claim":"Positioned NCK2 as a scaffold in the EphA4/RhoA axis in olfactory neurons under α-synuclein control, tying its abundance to neuronal projection.","evidence":"α-synuclein-KO mice, immunoprecipitation, iTRAQ-LC-MS, and overexpression rescue","pmids":["39543759"],"confidence":"Medium","gaps":["Direct NCK2-EphA4/RhoA binding interfaces not mapped","How α-synuclein controls NCK2 levels unknown"]},{"year":2024,"claim":"Identified KLF4 as a direct transcriptional activator of NCK2, embedding NCK2 in a miR-150-3p/KLF4 axis that modulates melanoma drug response.","evidence":"ChIP, promoter reporter assay, and overexpression/knockdown with Western blot","pmids":["38583810"],"confidence":"Medium","gaps":["Downstream NCK2 effectors in melanoma not identified","Single-context regulatory finding"]},{"year":2025,"claim":"Implicated NCK2 in clathrin-coated pit formation and EGF-driven PI3K/Akt signaling at the plasma membrane, suggesting a role in receptor-proximal endocytic signaling platforms.","evidence":"TIRFM CCP dynamics, Akt phosphorylation, and PI3K localization assays (preprint)","pmids":["bio_10.1101_2025.10.24.684344"],"confidence":"Medium","gaps":["Preprint, not peer-reviewed","NCK2-specific vs shared NCK1 contribution to CCPs not separated","Direct PI3K recruitment mechanism unmapped"]},{"year":null,"claim":"The molecular events linking NCK2's effector recruitment to specific small-GTPase activation (which GEFs it engages for RhoA vs Cdc42) and the structural/sequence basis for its paralog-specific cellular outputs despite SH2 specificity shared with NCK1 remain unresolved.","evidence":"","pmids":[],"confidence":"Medium","gaps":["No GEF directly bridging NCK2 to RhoA/Cdc42 identified","Midbody SH2 ligand in cytokinesis unknown","NCK2's own ubiquitination acceptor site (vs NCK1 Lys178) unmapped"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0060090","term_label":"molecular adaptor activity","supporting_discovery_ids":[0,3,5,19]}],"localization":[{"term_id":"GO:0005856","term_label":"cytoskeleton","supporting_discovery_ids":[0,13]},{"term_id":"GO:0005886","term_label":"plasma membrane","supporting_discovery_ids":[1,13,26]},{"term_id":"GO:0005634","term_label":"nucleus","supporting_discovery_ids":[7]}],"pathway":[{"term_id":"R-HSA-162582","term_label":"Signal Transduction","supporting_discovery_ids":[1,11,12]},{"term_id":"R-HSA-1640170","term_label":"Cell Cycle","supporting_discovery_ids":[19]},{"term_id":"R-HSA-1266738","term_label":"Developmental Biology","supporting_discovery_ids":[10,15,20]},{"term_id":"R-HSA-5653656","term_label":"Vesicle-mediated transport","supporting_discovery_ids":[26]}],"complexes":[],"partners":["PINCH","PDGFRB","DOCK180","IRS1","FAK","PAK3","ROBO","PAXILLIN"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"O43639","full_name":"Cytoplasmic protein NCK2","aliases":["Growth factor receptor-bound protein 4","NCK adaptor protein 2","Nck-2","SH2/SH3 adaptor protein NCK-beta"],"length_aa":380,"mass_kda":42.9,"function":"Adapter protein which associates with tyrosine-phosphorylated growth factor receptors or their cellular substrates. Maintains low levels of EIF2S1 phosphorylation by promoting its dephosphorylation by PP1. Plays a role in ELK1-dependent transcriptional activation in response to activated Ras signaling","subcellular_location":"Cytoplasm; Endoplasmic reticulum","url":"https://www.uniprot.org/uniprotkb/O43639/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/NCK2","classification":"Not Classified","n_dependent_lines":0,"n_total_lines":1208,"dependency_fraction":0.0},"opencell":{"profiled":true,"resolved_as":"","ensg_id":"ENSG00000071051","cell_line_id":"CID001533","localizations":[{"compartment":"vesicles","grade":3},{"compartment":"cytoplasmic","grade":2}],"interactors":[{"gene":"ARHGEF7","stoichiometry":0.2},{"gene":"PAK1","stoichiometry":0.2},{"gene":"PAK2","stoichiometry":0.2}],"url":"https://opencell.sf.czbiohub.org/target/CID001533","total_profiled":1310},"omim":[{"mim_id":"609692","title":"WAS/WASL-INTERACTING PROTEIN FAMILY, MEMBER 2; WIPF2","url":"https://www.omim.org/entry/609692"},{"mim_id":"605550","title":"RAS PROTEIN, DEXAMETHASONE-INDUCED, 1; RASD1","url":"https://www.omim.org/entry/605550"},{"mim_id":"604930","title":"NCK ADAPTOR PROTEIN 2; NCK2","url":"https://www.omim.org/entry/604930"},{"mim_id":"602716","title":"NEPHRIN; NPHS1","url":"https://www.omim.org/entry/602716"},{"mim_id":"600508","title":"NCK ADAPTOR PROTEIN 1; NCK1","url":"https://www.omim.org/entry/600508"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"","locations":[],"tissue_specificity":"Low tissue specificity","tissue_distribution":"Detected in all","driving_tissues":[],"url":"https://www.proteinatlas.org/search/NCK2"},"hgnc":{"alias_symbol":["NCKbeta"],"prev_symbol":[]},"alphafold":{"accession":"O43639","domains":[{"cath_id":"2.30.30.40","chopping":"5-57","consensus_level":"high","plddt":87.8425,"start":5,"end":57},{"cath_id":"2.30.30.40","chopping":"107-166","consensus_level":"high","plddt":75.5182,"start":107,"end":166},{"cath_id":"2.30.30.40","chopping":"198-256","consensus_level":"high","plddt":77.6664,"start":198,"end":256},{"cath_id":"3.30.505.10","chopping":"285-377","consensus_level":"high","plddt":88.4243,"start":285,"end":377}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/O43639","model_url":"https://alphafold.ebi.ac.uk/files/AF-O43639-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-O43639-F1-predicted_aligned_error_v6.png","plddt_mean":70.88},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=NCK2","jax_strain_url":"https://www.jax.org/strain/search?query=NCK2"},"sequence":{"accession":"O43639","fasta_url":"https://rest.uniprot.org/uniprotkb/O43639.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/O43639/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/O43639"}},"corpus_meta":[{"pmid":"9843575","id":"PMC_9843575","title":"Nck-2, a novel Src homology2/3-containing adaptor protein that interacts with the LIM-only protein PINCH and components of growth factor receptor kinase-signaling pathways.","date":"1998","source":"Molecular biology of the cell","url":"https://pubmed.ncbi.nlm.nih.gov/9843575","citation_count":166,"is_preprint":false},{"pmid":"16636066","id":"PMC_16636066","title":"The phosphotyrosine peptide binding specificity of Nck1 and Nck2 Src homology 2 domains.","date":"2006","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/16636066","citation_count":83,"is_preprint":false},{"pmid":"11027258","id":"PMC_11027258","title":"Nckbeta adapter regulates actin polymerization in NIH 3T3 fibroblasts in response to platelet-derived growth factor bb.","date":"2000","source":"Molecular and cellular biology","url":"https://pubmed.ncbi.nlm.nih.gov/11027258","citation_count":75,"is_preprint":false},{"pmid":"10026169","id":"PMC_10026169","title":"Identification of Grb4/Nckbeta, a src homology 2 and 3 domain-containing adapter protein having similar binding and biological properties to Nck.","date":"1999","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/10026169","citation_count":65,"is_preprint":false},{"pmid":"24287595","id":"PMC_24287595","title":"Proteasomal degradation of Nck1 but not Nck2 regulates RhoA activation and actin dynamics.","date":"2013","source":"Nature communications","url":"https://pubmed.ncbi.nlm.nih.gov/24287595","citation_count":51,"is_preprint":false},{"pmid":"11240126","id":"PMC_11240126","title":"Identification and kinetic analysis of the interaction between Nck-2 and DOCK180.","date":"2001","source":"FEBS letters","url":"https://pubmed.ncbi.nlm.nih.gov/11240126","citation_count":39,"is_preprint":false},{"pmid":"16752908","id":"PMC_16752908","title":"Structural insight into the binding diversity between the human Nck2 SH3 domains and proline-rich proteins.","date":"2006","source":"Biochemistry","url":"https://pubmed.ncbi.nlm.nih.gov/16752908","citation_count":37,"is_preprint":false},{"pmid":"21992144","id":"PMC_21992144","title":"Nck2 promotes human melanoma cell proliferation, migration and invasion in vitro and primary melanoma-derived tumor growth in vivo.","date":"2011","source":"BMC cancer","url":"https://pubmed.ncbi.nlm.nih.gov/21992144","citation_count":36,"is_preprint":false},{"pmid":"11950595","id":"PMC_11950595","title":"Nck-2 interacts with focal adhesion kinase and modulates cell motility.","date":"2002","source":"The international journal of biochemistry & cell biology","url":"https://pubmed.ncbi.nlm.nih.gov/11950595","citation_count":34,"is_preprint":false},{"pmid":"21949127","id":"PMC_21949127","title":"p21-Activated kinase 3 (PAK3) protein regulates synaptic transmission through its interaction with the Nck2/Grb4 protein adaptor.","date":"2011","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/21949127","citation_count":28,"is_preprint":false},{"pmid":"20219016","id":"PMC_20219016","title":"SKAP2, a novel target of HSF4b, associates with NCK2/F-actin at membrane ruffles and regulates actin reorganization in lens cell.","date":"2011","source":"Journal of cellular and molecular medicine","url":"https://pubmed.ncbi.nlm.nih.gov/20219016","citation_count":27,"is_preprint":false},{"pmid":"24670066","id":"PMC_24670066","title":"Non-overlapping functions of Nck1 and Nck2 adaptor proteins in T cell activation.","date":"2014","source":"Cell communication and signaling : CCS","url":"https://pubmed.ncbi.nlm.nih.gov/24670066","citation_count":26,"is_preprint":false},{"pmid":"17591694","id":"PMC_17591694","title":"Nckbeta adapter controls neuritogenesis by maintaining the cellular paxillin level.","date":"2007","source":"Molecular and cellular biology","url":"https://pubmed.ncbi.nlm.nih.gov/17591694","citation_count":26,"is_preprint":false},{"pmid":"30002203","id":"PMC_30002203","title":"Proteomic Analysis of NCK1/2 Adaptors Uncovers Paralog-specific Interactions That Reveal a New Role for NCK2 in Cell Abscission During Cytokinesis.","date":"2018","source":"Molecular & cellular proteomics : MCP","url":"https://pubmed.ncbi.nlm.nih.gov/30002203","citation_count":22,"is_preprint":false},{"pmid":"23349798","id":"PMC_23349798","title":"Association of HK2 and NCK2 with normal tension glaucoma in the Japanese population.","date":"2013","source":"PloS one","url":"https://pubmed.ncbi.nlm.nih.gov/23349798","citation_count":21,"is_preprint":false},{"pmid":"27325288","id":"PMC_27325288","title":"Nck2 Deficiency in Mice Results in Increased Adiposity Associated With Adipocyte Hypertrophy and Enhanced Adipogenesis.","date":"2016","source":"Diabetes","url":"https://pubmed.ncbi.nlm.nih.gov/27325288","citation_count":20,"is_preprint":false},{"pmid":"19242519","id":"PMC_19242519","title":"Non-compensating roles between Nckalpha and Nckbeta in PDGF-BB signaling to promote human dermal fibroblast migration.","date":"2009","source":"The Journal of investigative dermatology","url":"https://pubmed.ncbi.nlm.nih.gov/19242519","citation_count":20,"is_preprint":false},{"pmid":"15764601","id":"PMC_15764601","title":"Structural insight into the binding diversity between the Tyr-phosphorylated human ephrinBs and Nck2 SH2 domain.","date":"2005","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/15764601","citation_count":19,"is_preprint":false},{"pmid":"37292517","id":"PMC_37292517","title":"OIP5 Interacts with NCK2 to Mediate Human Spermatogonial Stem Cell Self-Renewal and Apoptosis through Cell Cyclins and Cycle Progression and Its Abnormality Is Correlated with Male Infertility.","date":"2023","source":"Research (Washington, D.C.)","url":"https://pubmed.ncbi.nlm.nih.gov/37292517","citation_count":17,"is_preprint":false},{"pmid":"11171109","id":"PMC_11171109","title":"Src homology 3 domain-dependent interaction of Nck-2 with insulin receptor substrate-1.","date":"2001","source":"The Biochemical journal","url":"https://pubmed.ncbi.nlm.nih.gov/11171109","citation_count":17,"is_preprint":false},{"pmid":"20637038","id":"PMC_20637038","title":"Cas utilizes Nck2 to activate Cdc42 and regulate cell polarization during cell migration in response to wound healing.","date":"2010","source":"The FEBS journal","url":"https://pubmed.ncbi.nlm.nih.gov/20637038","citation_count":16,"is_preprint":false},{"pmid":"18723748","id":"PMC_18723748","title":"Microsatellite analysis of the GLC1B locus on chromosome 2 points to NCK2 as a new candidate gene for normal tension glaucoma.","date":"2008","source":"The British journal of ophthalmology","url":"https://pubmed.ncbi.nlm.nih.gov/18723748","citation_count":16,"is_preprint":false},{"pmid":"21600986","id":"PMC_21600986","title":"The adaptor protein Nck2 mediates Slit1-induced changes in cortical neuron morphology.","date":"2011","source":"Molecular and cellular neurosciences","url":"https://pubmed.ncbi.nlm.nih.gov/21600986","citation_count":15,"is_preprint":false},{"pmid":"38583810","id":"PMC_38583810","title":"KLF4 suppresses anticancer effects of brusatol via transcriptional upregulating NCK2 expression in melanoma.","date":"2024","source":"Biochemical pharmacology","url":"https://pubmed.ncbi.nlm.nih.gov/38583810","citation_count":14,"is_preprint":false},{"pmid":"23706161","id":"PMC_23706161","title":"OSU-03012 sensitizes breast cancers to lapatinib-induced cell killing: a role for Nck1 but not Nck2.","date":"2013","source":"BMC cancer","url":"https://pubmed.ncbi.nlm.nih.gov/23706161","citation_count":14,"is_preprint":false},{"pmid":"32468886","id":"PMC_32468886","title":"Nck1, But Not Nck2, Mediates Disturbed Flow-Induced p21-Activated Kinase Activation and Endothelial Permeability.","date":"2020","source":"Journal of the American Heart Association","url":"https://pubmed.ncbi.nlm.nih.gov/32468886","citation_count":13,"is_preprint":false},{"pmid":"12074588","id":"PMC_12074588","title":"Brain-derived neurotrophic factor promotes interaction of the Nck2 adaptor protein with the TrkB tyrosine kinase receptor.","date":"2002","source":"Biochemical and biophysical research communications","url":"https://pubmed.ncbi.nlm.nih.gov/12074588","citation_count":13,"is_preprint":false},{"pmid":"23533358","id":"PMC_23533358","title":"NCK2 is significantly associated with opiates addiction in African-origin men.","date":"2013","source":"TheScientificWorldJournal","url":"https://pubmed.ncbi.nlm.nih.gov/23533358","citation_count":11,"is_preprint":false},{"pmid":"26004008","id":"PMC_26004008","title":"Targeting of the EGFR/β1 integrin connecting proteins PINCH1 and Nck2 radiosensitizes three-dimensional SCC cell cultures.","date":"2015","source":"Oncology reports","url":"https://pubmed.ncbi.nlm.nih.gov/26004008","citation_count":8,"is_preprint":false},{"pmid":"29218693","id":"PMC_29218693","title":"Non-catalytic region of tyrosine kinase adaptor protein 2 (NCK2) pathways as factor promoting aggressiveness in ovarian cancer.","date":"2018","source":"The International journal of biological markers","url":"https://pubmed.ncbi.nlm.nih.gov/29218693","citation_count":7,"is_preprint":false},{"pmid":"11514578","id":"PMC_11514578","title":"Grb4/Nckbeta acts as a nuclear repressor of v-Abl-induced transcription from c-jun/c-fos promoter elements.","date":"2001","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/11514578","citation_count":6,"is_preprint":false},{"pmid":"28425845","id":"PMC_28425845","title":"Nck2, an unexpected regulator of adipogenesis.","date":"2017","source":"Adipocyte","url":"https://pubmed.ncbi.nlm.nih.gov/28425845","citation_count":5,"is_preprint":false},{"pmid":"30016580","id":"PMC_30016580","title":"Nck2 is essential for limb trajectory selection by spinal motor axons.","date":"2018","source":"Developmental dynamics : an official publication of the American Association of Anatomists","url":"https://pubmed.ncbi.nlm.nih.gov/30016580","citation_count":5,"is_preprint":false},{"pmid":"30381256","id":"PMC_30381256","title":"Aristolochic acid inhibits Slit2-induced migration and tube formation via inactivation of Robo1/Robo2-NCK1/NCK2 signaling pathway in human umbilical vein endothelial cells.","date":"2018","source":"Toxicology letters","url":"https://pubmed.ncbi.nlm.nih.gov/30381256","citation_count":5,"is_preprint":false},{"pmid":"37479911","id":"PMC_37479911","title":"Distinct Requirements for Adaptor Proteins NCK1 and NCK2 in Mammary Gland Development.","date":"2023","source":"Journal of mammary gland biology and neoplasia","url":"https://pubmed.ncbi.nlm.nih.gov/37479911","citation_count":4,"is_preprint":false},{"pmid":"38312676","id":"PMC_38312676","title":"Mechanism of action of vinegared Cornu Cervi Degelatinatum in suppressing spleen kidney yang deficient ulcerative colitis through NCK2-JNK pathway.","date":"2024","source":"Heliyon","url":"https://pubmed.ncbi.nlm.nih.gov/38312676","citation_count":4,"is_preprint":false},{"pmid":"31512042","id":"PMC_31512042","title":"Association of HK2 and NCK2 with normal-tension glaucoma in a population from the Republic of Korea.","date":"2019","source":"Graefe's archive for clinical and experimental ophthalmology = Albrecht von Graefes Archiv fur klinische und experimentelle Ophthalmologie","url":"https://pubmed.ncbi.nlm.nih.gov/31512042","citation_count":3,"is_preprint":false},{"pmid":"36504051","id":"PMC_36504051","title":"[CBL inhibits proliferation and invasion of breast cancer cells by ubiquitylation-mediated degradation of NCK2].","date":"2022","source":"Nan fang yi ke da xue xue bao = Journal of Southern Medical University","url":"https://pubmed.ncbi.nlm.nih.gov/36504051","citation_count":2,"is_preprint":false},{"pmid":"39392452","id":"PMC_39392452","title":"Adapting to change: resolving the dynamic and dual roles of NCK1 and NCK2.","date":"2024","source":"The Biochemical journal","url":"https://pubmed.ncbi.nlm.nih.gov/39392452","citation_count":1,"is_preprint":false},{"pmid":"34589983","id":"PMC_34589983","title":"A Case of Lung Adenocarcinoma Harboring a Rare LOC285000-ALK-NCK2 Gene Fusion Identified by Next-Generation Sequencing With Long-Term Response to Crizotinib.","date":"2020","source":"JTO clinical and research reports","url":"https://pubmed.ncbi.nlm.nih.gov/34589983","citation_count":1,"is_preprint":false},{"pmid":"36035930","id":"PMC_36035930","title":"Endothelial NCK2 promotes atherosclerosis progression in male but not female Nck1-null atheroprone mice.","date":"2022","source":"Frontiers in cardiovascular medicine","url":"https://pubmed.ncbi.nlm.nih.gov/36035930","citation_count":0,"is_preprint":false},{"pmid":"39543759","id":"PMC_39543759","title":"A novel function for α-synuclein as a regulator of NCK2 in olfactory bulb: implications for its role in olfaction.","date":"2024","source":"Cell & bioscience","url":"https://pubmed.ncbi.nlm.nih.gov/39543759","citation_count":0,"is_preprint":false},{"pmid":null,"id":"bio_10.1101_2025.10.24.684344","title":"NCK adaptor proteins regulate clathrin-coated pit dynamics and EGF-stimulated PI3K-Akt signaling","date":"2025-10-26","source":"bioRxiv","url":"https://doi.org/10.1101/2025.10.24.684344","citation_count":0,"is_preprint":true}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":23602,"output_tokens":7217,"usd":0.08953,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":16322,"output_tokens":6335,"usd":0.119993,"stage2_stop_reason":"end_turn"},"total_usd":0.209523,"stage1_batch_id":"msgbatch_013a8chtv3AWyTqv4z4sEF4C","stage2_batch_id":"msgbatch_01AHsuW63vinsvuTgzmQ3n62","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 1998,\n      \"finding\": \"NCK2 (Nck-2) was identified as an adaptor protein comprising three N-terminal SH3 domains and one C-terminal SH2 domain. It interacts with PINCH via the fourth LIM domain of PINCH and the third SH3 domain of NCK2. NCK2 also binds EGF receptor (largely via its SH2 domain, with SH3 domains contributing), PDGF receptor-β (solely via SH2 domain, PDGF-dependent), and IRS-1 (primarily via second and third SH3 domains). A fraction of NCK2 was found associated with the cytoskeleton.\",\n      \"method\": \"Yeast two-hybrid, Co-IP, GST pulldown, domain mutagenesis\",\n      \"journal\": \"Molecular biology of the cell\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 / Strong — multiple orthogonal methods (yeast two-hybrid, Co-IP, pulldown, mutagenesis) in a single foundational paper establishing domain-specific interactions\",\n      \"pmids\": [\"9843575\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2000,\n      \"finding\": \"NCK2 (Nckbeta) plays a specific role in PDGF-BB-induced actin polymerization. Overexpression of NCK2 but not NCK1 blocks PDGF-stimulated membrane ruffling and lamellipodia. Mutation in either the SH2 or the middle SH3 domain abolishes this effect. NCK2 binds PDGFR-β at Tyr-1009 (distinct from NCK1's Tyr-751 binding site). Anti-NCK2 but not anti-NCK1 microinjection inhibits PDGF-stimulated actin polymerization. Constitutively membrane-bound NCK2 blocks Rac1-L62-induced membrane ruffling, suggesting NCK2 acts in parallel to or downstream of Rac1.\",\n      \"method\": \"Overexpression, dominant-negative mutants, microinjection of isoform-specific antibodies, site-directed mutagenesis\",\n      \"journal\": \"Molecular and cellular biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — multiple orthogonal methods (antibody microinjection, overexpression, mutagenesis, constitutively active constructs) establishing NCK2-specific function\",\n      \"pmids\": [\"11027258\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1999,\n      \"finding\": \"NCK2 (Grb4) associates with receptor tyrosine kinases and SH3-binding proteins PAK, Sos1, and PRK2. NCK2 synergizes with v-Abl and Sos1 to induce Elk-1-dependent gene expression and cooperates with v-Abl to transform NIH 3T3 cells.\",\n      \"method\": \"Co-IP, reporter gene assay, transformation assay\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — Co-IP and functional assays in single lab, multiple readouts\",\n      \"pmids\": [\"10026169\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2001,\n      \"finding\": \"NCK2 interacts with DOCK180 via its second and third SH3 domains. A major binding site maps to DOCK180 residues 1819–1836 (recognized primarily by the third SH3 domain). Two binding events occur with equilibrium dissociation constants of ~415 nM and ~3.24 nM. Both SH3 domains contribute cooperatively, with tandem SH3 domains greatly enhancing binding compared to individual domains alone.\",\n      \"method\": \"Yeast two-hybrid, GST pulldown, surface plasmon resonance, site-directed mutagenesis\",\n      \"journal\": \"FEBS letters\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — in vitro binding reconstitution with surface plasmon resonance kinetics plus mutagenesis, multiple orthogonal methods\",\n      \"pmids\": [\"11240126\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2001,\n      \"finding\": \"NCK2 SH3 domains directly interact with IRS-1 in vivo. Multiple SH3 domains (with conserved tryptophan residues critical) enhance complex formation. IRS-1 PTB/SAIN domain and Pre-C-terminal domain (but not PH domain) mediate NCK2 binding. The interaction is direct (occurs in absence of other proteins).\",\n      \"method\": \"Co-IP, GST pulldown, in vitro binding assay, deletion and point mutagenesis\",\n      \"journal\": \"The Biochemical journal\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — direct in vitro binding reconstitution plus mutagenesis of both partners, single lab but rigorous\",\n      \"pmids\": [\"11171109\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2002,\n      \"finding\": \"NCK2 interacts with focal adhesion kinase (FAK) through multiple SH2 and SH3 domains. The SH2-mediated interaction requires phosphorylation of FAK Tyr397. A fraction of NCK2 co-localizes with FAK at the cell periphery in spreading cells. Overexpression of NCK2 modestly decreases cell motility, whereas a SH2-only NCK2 mutant lacking SH3 domains significantly promotes motility.\",\n      \"method\": \"Co-IP, mutagenesis, immunofluorescence co-localization, overexpression motility assay\",\n      \"journal\": \"The international journal of biochemistry & cell biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — Co-IP with mutagenesis plus localization and functional assay, single lab\",\n      \"pmids\": [\"11950595\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2002,\n      \"finding\": \"BDNF stimulation promotes interaction of NCK2 with the TrkB tyrosine kinase receptor. Tyrosines Y694, Y695, and Y771 in the TrkB intracellular domain are crucial for this interaction. NCK2 was co-precipitated with GST-NCK2 recombinant protein or anti-Nck antibody from BDNF-activated cortical neurons.\",\n      \"method\": \"Yeast two-hybrid, GST pulldown, Co-IP from cortical neurons, mutagenesis\",\n      \"journal\": \"Biochemical and biophysical research communications\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — yeast two-hybrid plus GST pulldown and Co-IP from neurons, single lab\",\n      \"pmids\": [\"12074588\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2001,\n      \"finding\": \"NCK2 (Grb4) acts as a nuclear repressor of v-Abl-induced transcriptional activation from AP-1 and SRE promoter elements. This inhibitory activity is independent of direct v-Abl/NCK2 SH2 interaction; a SH2 domain mutant shows even stronger inhibition. The first two SH3 domains primarily mediate inhibitory function. The inhibitory activity is downstream of MEKK1 and JNK. Cell fractionation and fluorescence microscopy revealed that stronger inhibitory SH2 mutants show increased nuclear localization.\",\n      \"method\": \"Reporter gene assay, domain mutagenesis, cell fractionation, fluorescence microscopy\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — functional reporter assay with mutagenesis and subcellular fractionation, single lab\",\n      \"pmids\": [\"11514578\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2005,\n      \"finding\": \"The NMR solution structure of the human NCK2 SH2 domain was determined. It adopts the core SH2 fold but with a unique C-terminal antiparallel β-sheet not previously identified in other SH2 domains. The NCK2 SH2 domain binds three phosphorylated ephrinB2 fragments ([Tyr(P)304], [Tyr(P)316], and [Tyr(P)330]ephrinB2) via different mechanisms and with distinct conformational dynamics.\",\n      \"method\": \"NMR structure determination, NMR titration (HSQC), truncation mutagenesis\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — NMR structure with functional binding validation and mutagenesis, single lab but rigorous\",\n      \"pmids\": [\"15764601\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2006,\n      \"finding\": \"Crystal structures of NCK1 and NCK2 SH2 domains in complex with phosphopeptides from the EPEC protein Tir established that the SH2 domains of NCK1 and NCK2 have essentially indistinguishable phosphopeptide binding specificities. The second SH3 domain of NCK2 prefers APx#PxR motifs and the third SH3 domain prefers PxAPxR. NCK2 SH3 domains bind GIT1 (Arf-GAP) as experimentally confirmed. High-affinity binding of NCK2 SH3-3 to Nogo-A peptide was identified (Kd = 5.7 μM).\",\n      \"method\": \"X-ray crystallography, NMR (HSQC titration), isothermal titration calorimetry, binding assays\",\n      \"journal\": \"The Journal of biological chemistry / Biochemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — crystal structures plus ITC and NMR binding studies across two papers, replicated findings on binding specificity\",\n      \"pmids\": [\"16636066\", \"16752908\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2007,\n      \"finding\": \"NCK2 (Nckbeta), but not NCK1, is required for nerve growth factor-induced neurite outgrowth in PC12 cells and for normal axon/dendrite development in primary cortical neurons. NCK2 knockdown reduces steady-state paxillin levels specifically in neurons (not glia). NCK2 binds strongly to paxillin, preventing its proteasomal degradation. Re-expression of non-degradable NCK2 or forced paxillin expression rescues neuritogenesis in NCK2 knockdown cells.\",\n      \"method\": \"shRNA knockdown, overexpression rescue, Co-IP, proteasome inhibitor treatment, immunoblotting\",\n      \"journal\": \"Molecular and cellular biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — multiple orthogonal methods (knockdown, rescue, Co-IP, pharmacological inhibition) establishing NCK2-specific mechanism for paxillin stability in neurons\",\n      \"pmids\": [\"17591694\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2009,\n      \"finding\": \"NCK2 (Nckbeta) and NCK1 (Nckalpha) have non-compensating roles in PDGF-BB-induced dermal fibroblast migration. NCK2 binds PDGFR-β at Tyr-1009 and mediates Rho signaling to induce stress fibers, while NCK1 binds at Tyr-751 and mediates Cdc42 signaling for filopodium formation. Cells from NCK2-knockout mice and NCK2-knockdown human fibroblasts fail to migrate in response to PDGF-BB. The middle SH3 domain of NCK2 alone (dominant negative) blocks PDGF-BB-induced migration.\",\n      \"method\": \"Knockout MEFs, RNAi knockdown, site-directed mutagenesis of PDGFR-β, dominant-negative SH3 domain overexpression, Rho/Rac/Cdc42 activity assays\",\n      \"journal\": \"The Journal of investigative dermatology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — genetic KO combined with RNAi and receptor mutants plus GTPase activity measurements, multiple orthogonal approaches\",\n      \"pmids\": [\"19242519\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2010,\n      \"finding\": \"NCK2 is utilized by the integrin adaptor protein Cas (downstream of integrin signaling) to activate Cdc42 and induce cell polarization during wound healing. This is distinct from CrkII (also recruited by Cas) which activates Rac1 to promote cell protrusion extension.\",\n      \"method\": \"siRNA knockdown, Cdc42/Rac1 activity assays, wound healing assay\",\n      \"journal\": \"The FEBS journal\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — functional knockdown with GTPase activity assays, single lab\",\n      \"pmids\": [\"20637038\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2011,\n      \"finding\": \"NCK2 (Nck2) interacts with the SH2 domain of NCK2 via the N-terminus of SKAP2. The SKAP2-NCK2-F-actin complex accumulates at the leading edge of lamellipodia where FGF receptors and focal adhesions are also recruited. NCK2 participates in actin reorganization during lens epithelial cell differentiation.\",\n      \"method\": \"Co-IP, immunofluorescence co-localization, RNAi knockdown, overexpression with deletion mutants\",\n      \"journal\": \"Journal of cellular and molecular medicine\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — Co-IP plus co-localization and functional knockdown, single lab\",\n      \"pmids\": [\"20219016\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2011,\n      \"finding\": \"PAK3 interacts preferentially with NCK2 (over NCK1) in brain extracts and transfected cells, independent of PAK3 kinase activity. Selective uncoupling of NCK2 interactions using an interfering peptide in acute cortical slices causes rapid increase in evoked transmission. The PAK3-P12A mutation strongly reduces binding to NCK2 but only slightly to NCK1. Wild-type PAK3 decreases amplitude of spontaneous miniature excitatory currents, whereas P12A mutant does not, demonstrating that PAK3 down-regulates synaptic transmission through its interaction with NCK2.\",\n      \"method\": \"Co-IP from brain extracts and transfected cells, interfering peptide, electrophysiology in cortical slices, mutagenesis\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — Co-IP from native tissue plus interfering peptide plus electrophysiology plus mutagenesis, multiple orthogonal approaches linking NCK2-PAK3 interaction to synaptic function\",\n      \"pmids\": [\"21949127\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2011,\n      \"finding\": \"NCK2, but not NCK1, is required for Slit1-induced changes in cortical neuron morphology in vitro. NCK1 and NCK2 both bind to the Slit receptor Robo via an atypical SH3-mediated mechanism.\",\n      \"method\": \"shRNA knockdown (isoform-specific), Co-IP, morphological analysis of cortical neurons, Robo1/Robo2 knockout neurons\",\n      \"journal\": \"Molecular and cellular neurosciences\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — specific knockdown plus Co-IP identifying mechanism, single lab\",\n      \"pmids\": [\"21600986\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"NCK1, but not NCK2, is a substrate of c-Cbl-mediated ubiquitination at Lys178. Synaptopodin competes with c-Cbl for binding to NCK1, preventing NCK1 ubiquitination. Expression of c-Cbl-resistant NCK1(K178R) or NCK2 containing the SH3 domain 2 of NCK1 restores stress fibers in synaptopodin-depleted podocytes through RhoA signaling activation. NCK2 is not ubiquitinated by c-Cbl (negative finding that is mechanistically informative—NCK2 lacks the ubiquitin acceptor site equivalent, explaining its differential regulation).\",\n      \"method\": \"Ubiquitination assay, mutagenesis (K178R), c-Cbl knockdown, RhoA activity assay, domain-swap constructs\",\n      \"journal\": \"Nature communications\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 / Strong — ubiquitination assay with mutagenesis, domain swaps, and RhoA activity measurements establishing differential PTM regulation between NCK1 and NCK2\",\n      \"pmids\": [\"24287595\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"In human Jurkat T cells, NCK2 knockdown (to ~10%) reduces TCR-induced NFAT activation but does not significantly impair Erk/MEK phosphorylation, AP-1 activation, or IL-2/CD69 expression (in contrast to NCK1 knockdown). Thus NCK2 has a role in NFAT activation downstream of TCR but not in Erk pathway activation.\",\n      \"method\": \"shRNA knockdown (isoform-specific), luciferase reporter assays, phospho-immunoblotting\",\n      \"journal\": \"Cell communication and signaling\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — specific isoform knockdown with multiple signaling readouts, single lab\",\n      \"pmids\": [\"24670066\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"NCK2 deficiency in mice promotes adiposity with adipocyte hypertrophy and enhanced adipogenesis. Mechanistically, NCK2 deficiency in adipocyte precursors is associated with primed PERK activation and signaling, which promotes the adipogenic program including enhanced adipocyte differentiation, lipid droplet formation, and dysfunctional lipogenesis/lipolysis.\",\n      \"method\": \"Knockout mice, in vitro differentiation assays (3T3-L1, stromal vascular fraction), PERK signaling analysis\",\n      \"journal\": \"Diabetes\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — genetic KO with mechanistic pathway analysis (PERK signaling), single lab\",\n      \"pmids\": [\"27325288\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"NCK2 is required for cell abscission during cytokinesis. Nck2-/- (but not Nck1-/-) MEFs are multinucleated, display extended intercellular bridge protrusions, spend extended time in cytokinesis, and fail to complete abscission. The midbody in NCK2-deficient cells is longer and shows mislocalization of AURKB, PLK1, and ECT2. NCK2's SH2 domain is required for its cytokinesis function. AP-MS and BioID identified 28 proteins specifically associated with NCK2 (not NCK1).\",\n      \"method\": \"Knockout MEFs, AP-MS, BioID proximity labeling, live imaging, immunofluorescence, domain-swap/SH2 mutant rescue\",\n      \"journal\": \"Molecular & cellular proteomics\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — genetic KO with live imaging, two interactome methods (AP-MS + BioID), and domain mutagenesis rescue establishing NCK2-specific cytokinesis function\",\n      \"pmids\": [\"30002203\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"NCK2 is required for Eph-mediated motor axon trajectory selection in spinal lateral motor column neurons. NCK2 loss- and gain-of-function (via in ovo electroporation) perturbs LMC axon trajectory selection and growth preference against ephrins. NCK2 modulates α2-chimaerin activity in the context of Eph signaling.\",\n      \"method\": \"In ovo electroporation (loss- and gain-of-function), in vitro neurite growth assay with ephrins, epistasis with α2-chimaerin\",\n      \"journal\": \"Developmental dynamics\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — in vivo and in vitro loss/gain-of-function with epistasis analysis, single lab\",\n      \"pmids\": [\"30016580\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"NCK1 (not NCK2) mediates disturbed flow-induced endothelial permeability and PAK2 activation. Both NCK1 and NCK2 bind PECAM-1 in an SH2-dependent manner in response to shear stress, but only NCK1 ablation interferes with PAK2 membrane translocation and activation. Domain-swap experiments show NCK1 SH3 domains (specifically the first SH3) are critical for PAK recruitment and activation. NCK2 depletion has no significant effect on permeability (negative finding).\",\n      \"method\": \"Knockout cells, domain-swap constructs, in vivo partial carotid ligation, PAK activity assay, permeability assays (Evans blue, FITC-dextran), single-point SH3 mutations\",\n      \"journal\": \"Journal of the American Heart Association\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — in vivo KO model combined with domain swaps and mutagenesis plus in vitro functional readouts, distinguishing NCK1 vs NCK2 roles\",\n      \"pmids\": [\"32468886\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"CBL (Casitas B lymphoma E3 ubiquitin ligase) interacts with NCK2, promotes its ubiquitin-mediated proteasomal degradation, and thereby reduces NCK2 protein stability in breast cancer cells. NCK2 overexpression reverses CBL-mediated inhibition of cell proliferation and migration.\",\n      \"method\": \"Co-IP, IP-mass spectrometry, immunofluorescence co-localization, cycloheximide chase, ubiquitination assay, rescue overexpression\",\n      \"journal\": \"Nan fang yi ke da xue xue bao\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — multiple Co-IP methods plus ubiquitination assay and rescue experiment, single lab\",\n      \"pmids\": [\"36504051\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"OIP5 interacts with NCK2 in human spermatogonial stem cells (SSCs), as demonstrated by Co-IP, IP-MS, and GST pulldown. NCK2 silencing decreases SSC proliferation and DNA synthesis but enhances apoptosis. NCK2 knockdown reverses the influence of OIP5 overexpression on SSC self-renewal.\",\n      \"method\": \"Co-IP, IP-mass spectrometry, GST pulldown, siRNA knockdown, proliferation and apoptosis assays\",\n      \"journal\": \"Research (Washington, D.C.)\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — three orthogonal binding methods (Co-IP, IP-MS, GST pulldown) plus functional knockdown, single lab\",\n      \"pmids\": [\"37292517\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"NCK2 is associated with EphA4 and RhoA in the olfactory bulb (demonstrated by immunoprecipitation), functioning as a scaffolding protein to modulate EphA4/RhoA pathway. α-synuclein deletion reduces NCK2 levels and EphA4 activation; re-expressing α-synuclein reverses NCK2 downregulation and restores pEphA4 and RhoA activity, improving olfactory neuron projection.\",\n      \"method\": \"α-synuclein knockout mice, immunoprecipitation, iTRAQ-LC-MS, overexpression rescue\",\n      \"journal\": \"Cell & bioscience\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — Co-IP plus proteomic identification and genetic rescue in knockout mice, single lab\",\n      \"pmids\": [\"39543759\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"KLF4 transcription factor binds directly to the NCK2 promoter and facilitates NCK2 transcription, suppressing antitumor effects of brusatol in melanoma. The miR-150-3p/KLF4/NCK2 axis regulates brusatol's anti-melanoma activity.\",\n      \"method\": \"ChIP, promoter reporter assay, overexpression and knockdown, Western blot\",\n      \"journal\": \"Biochemical pharmacology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — ChIP demonstrating direct promoter binding plus functional rescue experiments, single lab\",\n      \"pmids\": [\"38583810\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"NCK2 (and NCK1) are enriched within clathrin-coated pits (CCPs) at the plasma membrane and regulate early CCP formation and maturation. NCK2 supports EGF-stimulated Akt phosphorylation. EGF stimulation triggers NCK-dependent enrichment of PI3K within CCPs. Perturbation of NCK adaptors suppresses cell proliferation and survival.\",\n      \"method\": \"TIRFM (total internal reflection fluorescence microscopy), CCP dynamics analysis, Akt phosphorylation assay, PI3K localization\",\n      \"journal\": \"bioRxiv\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — live TIRFM imaging with functional signaling readouts, preprint not yet peer-reviewed\",\n      \"pmids\": [\"bio_10.1101_2025.10.24.684344\"],\n      \"is_preprint\": true\n    }\n  ],\n  \"current_model\": \"NCK2 is an SH2/SH3 adaptor protein that links activated receptor tyrosine kinases (EGFR, PDGFRβ at Tyr-1009, TrkB) and integrin signaling components (FAK, PINCH, IRS-1, Cas) to cytoplasmic effectors (DOCK180, PAK3, paxillin, Robo, α2-chimaerin) via domain-specific interactions, thereby regulating actin cytoskeleton dynamics, cell migration, neurite outgrowth, synaptic transmission, cytokinesis abscission, and adipogenesis, with its abundance controlled by CBL-mediated ubiquitination (from which NCK2 is less susceptible than NCK1) and KLF4-driven transcription, and its signaling specificity determined by the unique binding preferences of its three SH3 domains and SH2 domain relative to the closely related NCK1 paralog.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"NCK2 is a modular SH2/SH3 adaptor protein that couples activated receptor tyrosine kinases and adhesion receptors to actin-regulatory effectors, thereby controlling cytoskeletal dynamics, cell migration, neuronal morphogenesis, and cytokinesis [#0, #1, #11]. Built from three N-terminal SH3 domains and a single C-terminal SH2 domain, it engages receptors through phosphotyrosine-dependent SH2 binding — EGFR, PDGFR-\\u03b2 at Tyr-1009, TrkB, and the integrin scaffold FAK at phospho-Tyr397 — while its tandem SH3 domains recruit downstream effectors including DOCK180, PAK3, IRS-1, paxillin, GIT1, and Robo [#0, #1, #3, #5, #6, #9, #15]. Its three SH3 modules carry distinct binding preferences (SH3-2 favoring APxxPxR and SH3-3 favoring PxAPxR motifs, with tandem domains binding cooperatively), and although the NCK2 SH2 domain is structurally distinguished by a unique C-terminal antiparallel \\u03b2-sheet, its phosphopeptide specificity is essentially indistinguishable from NCK1, implying that functional divergence between the paralogs arises largely from SH3-domain selectivity and differential regulation [#3, #8, #9]. Through these interactions NCK2 directs specific small-GTPase outputs: it transmits PDGFR-\\u03b2 Tyr-1009 signals to RhoA-driven stress fibers (whereas NCK1 routes Tyr-751 to Cdc42) and is recruited by the integrin adaptor Cas to activate Cdc42 for polarized migration [#11, #12]. NCK2 has non-redundant, NCK1-independent roles in NGF- and Slit1-induced neurite outgrowth — in part by binding paxillin and protecting it from proteasomal degradation — in PAK3-dependent down-regulation of synaptic transmission, in Eph-mediated motor axon guidance via \\u03b12-chimaerin, and in completing cytokinetic abscission, where its SH2 domain is required for proper midbody localization of AURKB, PLK1, and ECT2 [#10, #14, #15, #19, #20]. NCK2 abundance is set post-translationally by CBL-mediated ubiquitin-proteasomal degradation and transcriptionally by KLF4, and unlike NCK1 it lacks the Lys178 c-Cbl ubiquitination acceptor site, providing a molecular basis for paralog-specific stability [#16, #22, #25].\",\n  \"teleology\": [\n    {\n      \"year\": 1998,\n      \"claim\": \"Established NCK2 as a distinct SH2/SH3 adaptor and defined its first domain-specific receptor and scaffold interactions, framing it as a modular signaling linker rather than a redundant NCK1 copy.\",\n      \"evidence\": \"Yeast two-hybrid, Co-IP, GST pulldown and domain mutagenesis mapping PINCH, EGFR, PDGFR-\\u03b2 and IRS-1 contacts\",\n      \"pmids\": [\"9843575\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not establish functional output of these interactions\", \"Cytoskeletal association observed but mechanism undefined\"]\n    },\n    {\n      \"year\": 2000,\n      \"claim\": \"Demonstrated NCK2 has a function not shared by NCK1 in PDGF-induced actin remodeling, providing the first evidence of paralog-specific signaling.\",\n      \"evidence\": \"Isoform-specific antibody microinjection, overexpression, and SH2/SH3 mutants in fibroblasts, mapping NCK2 to PDGFR-\\u03b2 Tyr-1009\",\n      \"pmids\": [\"11027258\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Effector linking NCK2 to actin not yet identified\", \"Relationship to Rac1 inferred from epistasis only\"]\n    },\n    {\n      \"year\": 2001,\n      \"claim\": \"Resolved how NCK2 SH3 domains achieve high-affinity, cooperative effector binding (DOCK180, IRS-1), explaining how tandem domains generate signaling specificity and avidity.\",\n      \"evidence\": \"SPR kinetics, GST pulldown, and point mutagenesis of tandem SH3 domains and partner motifs\",\n      \"pmids\": [\"11240126\", \"11171109\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Cellular consequence of DOCK180 recruitment not tested here\", \"In vivo stoichiometry of cooperative binding unknown\"]\n    },\n    {\n      \"year\": 2002,\n      \"claim\": \"Connected NCK2 to focal-adhesion (FAK) and neurotrophin (TrkB) signaling, broadening its receptor repertoire to adhesion and neuronal contexts.\",\n      \"evidence\": \"Co-IP, phospho-Tyr397-dependent SH2 binding, co-localization and motility assays; BDNF-dependent TrkB Co-IP from cortical neurons\",\n      \"pmids\": [\"11950595\", \"12074588\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Opposing motility effects of full-length vs SH2-only NCK2 not mechanistically resolved\", \"TrkB downstream pathway not defined\"]\n    },\n    {\n      \"year\": 2005,\n      \"claim\": \"Provided the structural basis for NCK2 SH2 recognition and revealed a unique fold feature plus multimodal ephrinB2 phosphopeptide binding.\",\n      \"evidence\": \"NMR solution structure and HSQC titrations with phospho-ephrinB2 fragments\",\n      \"pmids\": [\"15764601\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Functional role of the unique C-terminal \\u03b2-sheet untested\", \"ephrinB2-NCK2 cellular signaling not addressed\"]\n    },\n    {\n      \"year\": 2006,\n      \"claim\": \"Defined SH3 motif preferences and showed that NCK1 and NCK2 SH2 domains have indistinguishable phosphopeptide specificity, localizing paralog divergence to SH3 domains.\",\n      \"evidence\": \"X-ray crystallography, ITC, and NMR with Tir, GIT1 and Nogo-A peptides\",\n      \"pmids\": [\"16636066\", \"16752908\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Does not explain how indistinguishable SH2 domains produce divergent receptor coupling in cells\", \"GIT1/Nogo-A functional roles not tested\"]\n    },\n    {\n      \"year\": 2007,\n      \"claim\": \"Identified an NCK2-specific mechanism in neurons: stabilizing paxillin against proteasomal degradation to enable neurite outgrowth, establishing a non-adaptor (protein-stability) role.\",\n      \"evidence\": \"Isoform-specific shRNA, Co-IP, proteasome inhibition, and non-degradable NCK2/paxillin rescue in PC12 and cortical neurons\",\n      \"pmids\": [\"17591694\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Molecular basis of NCK2-dependent paxillin protection unclear\", \"Why effect is neuron-specific not explained\"]\n    },\n    {\n      \"year\": 2009,\n      \"claim\": \"Showed NCK1 and NCK2 are non-compensating, routing the same receptor to distinct GTPases (NCK2\\u2192RhoA/stress fibers at Tyr-1009; NCK1\\u2192Cdc42/filopodia at Tyr-751).\",\n      \"evidence\": \"NCK2-KO MEFs, RNAi, PDGFR-\\u03b2 site mutants, dominant-negative SH3, and GTPase activity assays\",\n      \"pmids\": [\"19242519\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Intermediate GEF/effector linking NCK2 to RhoA not defined\", \"Generality beyond fibroblasts untested\"]\n    },\n    {\n      \"year\": 2010,\n      \"claim\": \"Placed NCK2 downstream of integrin/Cas signaling as a Cdc42 activator for cell polarization, distinguishing it from CrkII-driven Rac1 protrusion.\",\n      \"evidence\": \"siRNA knockdown, GTPase activity assays, and wound-healing assays\",\n      \"pmids\": [\"20637038\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct NCK2-Cas binding mode not mapped here\", \"GEF coupling NCK2 to Cdc42 unknown\"]\n    },\n    {\n      \"year\": 2011,\n      \"claim\": \"Extended NCK2-specific functions into neuronal guidance, synaptic transmission, and lamellipodial actin assembly through Robo, PAK3, and SKAP2 partners.\",\n      \"evidence\": \"Isoform-specific knockdown, Co-IP from brain, interfering peptide plus electrophysiology, and leading-edge co-localization\",\n      \"pmids\": [\"21949127\", \"21600986\", \"20219016\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Atypical SH3-mediated Robo binding mode not structurally defined\", \"How NCK2-PAK3 down-regulates transmission mechanistically open\"]\n    },\n    {\n      \"year\": 2013,\n      \"claim\": \"Explained paralog-specific stability: NCK1 is ubiquitinated by c-Cbl at Lys178 while NCK2 lacks the acceptor site, accounting for differential turnover and signaling persistence.\",\n      \"evidence\": \"Ubiquitination assays, K178R mutagenesis, domain swaps, and RhoA activity assays in podocytes\",\n      \"pmids\": [\"24287595\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Whether NCK2 has its own degradation pathway not addressed here\", \"Functional consequence of NCK2 stability in this context not isolated\"]\n    },\n    {\n      \"year\": 2014,\n      \"claim\": \"Distinguished NCK2 signaling output in T cells, linking it selectively to TCR-induced NFAT activation rather than the Erk/AP-1 axis used by NCK1.\",\n      \"evidence\": \"Isoform-specific shRNA, luciferase reporters, and phospho-immunoblotting in Jurkat cells\",\n      \"pmids\": [\"24670066\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Molecular link from NCK2 to NFAT not defined\", \"Direct TCR-proximal partners in this pathway not identified\"]\n    },\n    {\n      \"year\": 2016,\n      \"claim\": \"Revealed a metabolic role: NCK2 restrains adipogenesis by suppressing PERK signaling in adipocyte precursors.\",\n      \"evidence\": \"NCK2-KO mice and in vitro differentiation assays with PERK signaling analysis\",\n      \"pmids\": [\"27325288\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct NCK2-PERK molecular link unestablished\", \"Adaptor partners in adipocytes not mapped\"]\n    },\n    {\n      \"year\": 2018,\n      \"claim\": \"Defined an NCK1-independent requirement for NCK2 in cytokinetic abscission, with its SH2 domain needed for proper midbody localization of AURKB, PLK1 and ECT2, and an NCK2-specific interactome.\",\n      \"evidence\": \"NCK2-KO MEFs, live imaging, AP-MS and BioID, and SH2-mutant rescue\",\n      \"pmids\": [\"30002203\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Direct SH2 ligand at the midbody not identified\", \"Mechanism positioning AURKB/PLK1/ECT2 via NCK2 unresolved\"]\n    },\n    {\n      \"year\": 2018,\n      \"claim\": \"Showed NCK2 is required for Eph/ephrin-guided motor axon trajectory selection by modulating \\u03b12-chimaerin.\",\n      \"evidence\": \"In ovo electroporation loss/gain-of-function, ephrin neurite assays, and \\u03b12-chimaerin epistasis\",\n      \"pmids\": [\"30016580\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct NCK2-\\u03b12-chimaerin binding not biochemically mapped\", \"Eph receptor coupling specificity unresolved\"]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"Sharpened paralog distinction in endothelium: both adaptors bind PECAM-1 under shear, but only NCK1 (via its first SH3) drives PAK2 activation and permeability, with NCK2 dispensable.\",\n      \"evidence\": \"Knockout cells, domain swaps, single-point SH3 mutants, in vivo carotid ligation, and permeability/PAK assays\",\n      \"pmids\": [\"32468886\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"NCK2's role at PECAM-1, if any, not defined\", \"Why NCK2 SH3 domains fail to recruit PAK here unexplained\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Identified CBL as an E3 ligase driving NCK2 ubiquitin-proteasomal degradation, controlling NCK2 abundance and its pro-proliferative/migratory output in cancer.\",\n      \"evidence\": \"Co-IP, IP-MS, cycloheximide chase, ubiquitination assay, and rescue overexpression in breast cancer cells\",\n      \"pmids\": [\"36504051\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"NCK2 ubiquitination acceptor site not mapped (contrast with NCK1 Lys178)\", \"Single-lab finding without in vivo validation\"]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"Linked NCK2 to spermatogonial stem cell self-renewal as an OIP5 effector promoting proliferation and survival.\",\n      \"evidence\": \"Co-IP, IP-MS, GST pulldown, and siRNA functional assays in human SSCs\",\n      \"pmids\": [\"37292517\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Domain mediating OIP5-NCK2 interaction unmapped\", \"Downstream signaling in SSCs undefined\"]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Positioned NCK2 as a scaffold in the EphA4/RhoA axis in olfactory neurons under \\u03b1-synuclein control, tying its abundance to neuronal projection.\",\n      \"evidence\": \"\\u03b1-synuclein-KO mice, immunoprecipitation, iTRAQ-LC-MS, and overexpression rescue\",\n      \"pmids\": [\"39543759\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct NCK2-EphA4/RhoA binding interfaces not mapped\", \"How \\u03b1-synuclein controls NCK2 levels unknown\"]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Identified KLF4 as a direct transcriptional activator of NCK2, embedding NCK2 in a miR-150-3p/KLF4 axis that modulates melanoma drug response.\",\n      \"evidence\": \"ChIP, promoter reporter assay, and overexpression/knockdown with Western blot\",\n      \"pmids\": [\"38583810\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Downstream NCK2 effectors in melanoma not identified\", \"Single-context regulatory finding\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Implicated NCK2 in clathrin-coated pit formation and EGF-driven PI3K/Akt signaling at the plasma membrane, suggesting a role in receptor-proximal endocytic signaling platforms.\",\n      \"evidence\": \"TIRFM CCP dynamics, Akt phosphorylation, and PI3K localization assays (preprint)\",\n      \"pmids\": [\"bio_10.1101_2025.10.24.684344\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Preprint, not peer-reviewed\", \"NCK2-specific vs shared NCK1 contribution to CCPs not separated\", \"Direct PI3K recruitment mechanism unmapped\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"The molecular events linking NCK2's effector recruitment to specific small-GTPase activation (which GEFs it engages for RhoA vs Cdc42) and the structural/sequence basis for its paralog-specific cellular outputs despite SH2 specificity shared with NCK1 remain unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No GEF directly bridging NCK2 to RhoA/Cdc42 identified\", \"Midbody SH2 ligand in cytokinesis unknown\", \"NCK2's own ubiquitination acceptor site (vs NCK1 Lys178) unmapped\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0060090\", \"supporting_discovery_ids\": [0, 3, 5, 19]},\n      {\"term_id\": \"GO:0005070\", \"supporting_discovery_ids\": [0]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005856\", \"supporting_discovery_ids\": [0, 13]},\n      {\"term_id\": \"GO:0005886\", \"supporting_discovery_ids\": [1, 13, 26]},\n      {\"term_id\": \"GO:0005634\", \"supporting_discovery_ids\": [7]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-162582\", \"supporting_discovery_ids\": [1, 11, 12]},\n      {\"term_id\": \"R-HSA-1640170\", \"supporting_discovery_ids\": [19]},\n      {\"term_id\": \"R-HSA-1266738\", \"supporting_discovery_ids\": [10, 15, 20]},\n      {\"term_id\": \"R-HSA-5653656\", \"supporting_discovery_ids\": [26]}\n    ],\n    \"complexes\": [],\n    \"partners\": [\"PINCH\", \"PDGFRB\", \"DOCK180\", \"IRS1\", \"FAK\", \"PAK3\", \"ROBO\", \"paxillin\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":6,"faith_total":6,"faith_pct":100.0}}