{"gene":"SYK","run_date":"2026-04-28T21:42:57","timeline":{"discoveries":[{"year":2001,"finding":"Syk binds directly to the integrin β3 cytoplasmic tail through its tandem SH2 domains in a phosphotyrosine-independent manner, and this interaction is required for Syk activation and lamellipodia formation upon cell adhesion to fibrinogen; deletion of the four C-terminal residues of β3 abolished Syk binding, activation, and lamellipodia formation without affecting FAK phosphorylation.","method":"Co-immunoprecipitation, pulldown with β3 cytoplasmic tail, cell adhesion assay with mutant integrin (β3-759X), kinase activity assay","journal":"Current biology : CB","confidence":"High","confidence_rationale":"Tier 2 — reciprocal binding assays plus functional mutagenesis with defined cellular phenotype","pmids":["11719224"],"is_preprint":false},{"year":1996,"finding":"Clustered Syk kinase domains are sufficient to autonomously trigger phagocytosis and filamentous actin redistribution in COS cells; a catalytic-domain point mutation abolishes this activity, and the kinase domain alone is sufficient for cytoskeletal coupling.","method":"Chimeric transmembrane receptor expression in COS cells, phagocytosis assay, actin redistribution assay, catalytic-dead point mutant","journal":"Proceedings of the National Academy of Sciences of the United States of America","confidence":"High","confidence_rationale":"Tier 1 — reconstitution with mutagenesis establishing catalytic requirement","pmids":["8577722"],"is_preprint":false},{"year":2001,"finding":"BLNK mediates Syk-dependent Btk activation: Syk phosphorylates Btk on Tyr-551 via BLNK as a scaffold, requiring the Btk-SH2 domain interaction with BLNK; BCR-induced Btk phosphorylation and activation are significantly reduced in both BLNK-deficient and Syk-deficient B cells.","method":"Reconstitution cell system co-expression, in vitro phosphorylation assay, BLNK-deficient and Syk-deficient B cell analysis","journal":"Proceedings of the National Academy of Sciences of the United States of America","confidence":"High","confidence_rationale":"Tier 1 — reconstitution assay with genetic validation in deficient cells","pmids":["11226282"],"is_preprint":false},{"year":2010,"finding":"CLEC-2 activates Syk through receptor dimerization: the single YxxL hemITAM in the CLEC-2 cytosolic tail, when phosphorylated, recruits Syk tandem SH2 domains in a 2:1 (CLEC-2:Syk) stoichiometry; CLEC-2 exists as a dimer in resting platelets and forms larger complexes upon activation.","method":"Peptide pulldown, surface plasmon resonance, quantitative Western blot, tryptophan fluorescence, competition experiments, cross-linking, electron microscopy","journal":"Blood","confidence":"High","confidence_rationale":"Tier 1 — multiple orthogonal biophysical and biochemical methods in a single study","pmids":["20154219"],"is_preprint":false},{"year":2012,"finding":"Crystal structures of full-length Syk (wild type and Y348F/Y352F mutant) in complex with AMP-PNP reveal an autoinhibited conformation; pITAM binding to the tSH2 domain stimulates in vitro autophosphorylation and confers conformational changes at the ATP-binding site of the kinase domain, consistent with allosteric activation.","method":"X-ray crystallography of full-length Syk, surface plasmon resonance, isothermal titration calorimetry, in vitro autophosphorylation assay, mutagenesis (Y348F/Y352F)","journal":"Journal of molecular biology","confidence":"High","confidence_rationale":"Tier 1 — crystal structure plus multiple orthogonal biochemical methods with mutagenesis","pmids":["23154170"],"is_preprint":false},{"year":2019,"finding":"SYK activation requires both ppITAM binding (which primes SYK) and LYN-mediated phosphorylation of Tyr-352 then Tyr-348 in the SH2-kinase linker, which then facilitates activation-loop phosphorylation and full SYK activation; ppITAM alone is insufficient to fully activate monomeric untagged SYK.","method":"In vitro kinase assay with unphosphorylated and phosphorylated recombinant SYK (monomeric and obligatory-dimeric forms), immunoblot, phosphoproteomics","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1 — reconstituted in vitro kinase system with phosphoproteomic site mapping","pmids":["30923129"],"is_preprint":false},{"year":2010,"finding":"Syk tyrosine 346 in FcεRI signaling is exclusively phosphorylated by Src family kinases (predominantly Lyn), while tyrosines 317, 342, 519, and 520 are phosphorylated by both Syk auto/trans-phosphorylation and Src family kinases; Lyn knockdown impairs phosphorylation of Syk substrates SLP-76 and LAT but paradoxically sensitizes cells to degranulation by enhancing distal ERK activation.","method":"Selective kinase inhibitors, kinase-dead Syk, Lyn siRNA knockdown, site-specific phospho-antibodies in RBL-2H3 and bone marrow-derived mast cells","journal":"Molecular immunology","confidence":"High","confidence_rationale":"Tier 1/2 — multiple orthogonal approaches (pharmacologic inhibition, siRNA, KD mutant) with site-specific readouts","pmids":["20828828"],"is_preprint":false},{"year":2010,"finding":"C-terminal tyrosines Tyr-623, Tyr-624, and Tyr-625 of Syk regulate its kinase activity and ITAM binding: mutation of these residues increases basal autophosphorylation and reduces kinase activity toward exogenous substrates, decreases ITAM binding, and impairs FcεRI-induced degranulation, NFAT, NFκB, and MAP kinase activation; Tyr-625 has the dominant role.","method":"Site-directed mutagenesis, in vitro kinase assay, ITAM binding assay, degranulation assay, signaling readouts in Syk-deficient mast cells reconstituted with wild-type or mutant Syk","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1 — in vitro assay plus mutagenesis with functional cellular reconstitution","pmids":["20554527"],"is_preprint":false},{"year":1995,"finding":"ZAP-70 and Syk are functionally homologous: ZAP-70 expression in Syk-deficient B cells reconstitutes BCR function, requiring intact SH2 and catalytic domains; both kinases bind directly to phosphorylated Igα and Igβ subunits with comparable affinities.","method":"Reconstitution of Syk-deficient B cells with ZAP-70, direct binding assay to phosphorylated BCR subunits, domain-deletion mutants","journal":"Immunity","confidence":"High","confidence_rationale":"Tier 1 — genetic reconstitution plus direct binding assays","pmids":["7538440"],"is_preprint":false},{"year":2006,"finding":"Syk is required for pathogen engulfment in complement-mediated phagocytosis (via CR3): Syk becomes tyrosine-phosphorylated and accumulates around nascent phagosomes during C3bi-opsonized zymosan uptake; Syk-siRNA or dominant-negative Syk impairs engulfment, actin accumulation/depolymerization around phagosomes, and RhoA activation/Vav tyrosine phosphorylation.","method":"siRNA knockdown, dominant-negative Syk expression, fluorescence quenching phagocytosis assay, immunofluorescence, tyrosine phosphorylation assay in HL60 cells","journal":"Blood","confidence":"High","confidence_rationale":"Tier 2 — multiple orthogonal genetic approaches with defined mechanistic pathway readouts","pmids":["16449524"],"is_preprint":false},{"year":2012,"finding":"Jedi-1 and MEGF10 signal engulfment of apoptotic neurons through Syk: Syk interacts with the ITAMs of both receptors; ITAM phosphorylation by Src family kinases enhances Syk interaction and activation; ITAM tyrosine mutation or Syk inhibition blocks phagocytosis of microspheres and apoptotic neurons in glial precursor cocultures.","method":"Co-immunoprecipitation, ITAM tyrosine mutagenesis, pharmacologic Syk inhibition (BAY 61-3606), Syk siRNA knockdown in mouse embryonic glial precursors, engulfment assay","journal":"The Journal of neuroscience : the official journal of the Society for Neuroscience","confidence":"High","confidence_rationale":"Tier 2 — reciprocal Co-IP plus mutagenesis plus genetic KD with defined phagocytic phenotype","pmids":["22993420"],"is_preprint":false},{"year":2014,"finding":"Retroviral retention induces phosphorylation of conserved tyrosines in tetherin cytoplasmic tail dimers, recruiting Syk; Syk is required for downstream NF-κB activation; tetherin signaling is coupled to cortical actin via RICH2 (ARHGAP44), and a naturally occurring tetherin polymorphism with reduced RICH2 binding shows decreased tetherin phosphorylation and NF-κB activation.","method":"Co-immunoprecipitation, phosphorylation assays, NF-κB reporter assay, tetherin polymorphism analysis, retroviral particle retention assay","journal":"Cell host & microbe","confidence":"High","confidence_rationale":"Tier 2 — multiple orthogonal methods linking Syk recruitment to functional NF-κB signaling with natural variant validation","pmids":["25211072"],"is_preprint":false},{"year":2021,"finding":"TRIM31 E3 ligase catalyzes K27-linked polyubiquitination of SYK at Lys-375 and Lys-517, promoting SYK plasma membrane translocation and binding to C-type lectin receptors, and preventing interaction with the phosphatase SHP-1; Trim31-deficient macrophages and dendritic cells show dampened SYK-mediated signaling and impaired cytokine responses to Candida albicans.","method":"Co-immunoprecipitation, ubiquitination assay, site-directed mutagenesis (K375/K517), subcellular fractionation, Trim31-/- mouse model, in vitro infection assay","journal":"Signal transduction and targeted therapy","confidence":"High","confidence_rationale":"Tier 2 — reconstituted ubiquitination assay with mutagenesis, validated in KO mouse model","pmids":["34362877"],"is_preprint":false},{"year":2020,"finding":"USP10 is a major deubiquitinase required for SYK protein stabilization; USP10 inhibition induces SYK degradation via the proteasome and kills cells driven by active SYK or oncogenic FLT3.","method":"USP10 inhibitor treatment, SYK protein stability assays, cell viability assays, co-immunoprecipitation","journal":"British journal of cancer","confidence":"Medium","confidence_rationale":"Tier 2 — pharmacologic and biochemical evidence, single lab","pmids":["32015510"],"is_preprint":false},{"year":2004,"finding":"IgE/FcεRI stimulation of basophils leads to c-Cbl phosphorylation, c-Cbl association with Syk, Syk ubiquitylation, and proteasome-dependent Syk degradation over hours; proteasome inhibition with lactacystin A results in accumulation of high-molecular-weight ubiquitylated Syk species.","method":"Immunoprecipitation, immunoblotting, proteasome inhibition (lactacystin A), primary human basophils","journal":"The Journal of allergy and clinical immunology","confidence":"Medium","confidence_rationale":"Tier 2 — Co-IP plus pharmacological inhibition establishing ubiquitin-proteasome regulation","pmids":["15577829"],"is_preprint":false},{"year":2020,"finding":"Cbl-mediated Syk degradation in germinal center B cells attenuates BCR signaling intensity by mitigating Kras/Erk and PI3K/Foxo1 pathways, restraining plasma cell formation and promoting light-zone-to-dark-zone transition.","method":"Mouse model defective in Cbl-mediated Syk degradation, gene expression analysis, flow cytometry, signaling pathway analysis","journal":"The Journal of experimental medicine","confidence":"Medium","confidence_rationale":"Tier 2 — genetic mouse model with defined pathway readouts, single lab","pmids":["31873727"],"is_preprint":false},{"year":2006,"finding":"Syk shuttles between nuclear and cytoplasmic compartments via an unconventional shuttling sequence at the junction of the catalytic domain and linker B region; BCR engagement causes nuclear exclusion of Syk through protein kinase C activation and new protein synthesis; nuclear exclusion promotes stress-induced caspase-3 activation.","method":"Deletion mutant analysis, subcellular fractionation, live-cell imaging, pharmacological inhibitors (PKC), caspase-3 activation assays","journal":"Molecular and cellular biology","confidence":"Medium","confidence_rationale":"Tier 2 — domain-deletion mapping plus functional consequence in B cells","pmids":["16611990"],"is_preprint":false},{"year":2005,"finding":"Syk colocalizes and copurifies with the centrosomal marker γ-tubulin, exhibits catalytic activity within centrosomes, requires intact kinase activity for centrosomal localization, and is degraded via ubiquitinylation/proteasome during mitosis; unrestrained Syk overexpression causes multipolar spindles, supernumerary centrosomes, and mitotic catastrophe.","method":"Colocalization by immunofluorescence, centrosome purification/copurification, in vitro kinase assay, DsRed-Syk overexpression, live-cell imaging","journal":"Cancer research","confidence":"Medium","confidence_rationale":"Tier 2 — subcellular fractionation with kinase activity assay and functional overexpression phenotype","pmids":["16322234"],"is_preprint":false},{"year":2002,"finding":"In NK cells, Syk acts upstream of PI3K in the DAP12-mediated cytotoxicity pathway: tumor cell ligation induces DAP12 tyrosine phosphorylation and DAP12-Syk association; kinase-deficient Syk or Syk inhibitor blocks PI3K, Rac1, PAK1, MEK, and ERK activation as well as perforin movement and NK cytotoxicity; constitutively active PI3K rescues all downstream events in Syk-impaired cells.","method":"Dominant-negative Syk expression, pharmacological inhibition (piceatannol), constitutively active PI3K rescue, co-immunoprecipitation, kinase activity assays, cytotoxicity assays","journal":"Journal of immunology (Baltimore, Md. : 1950)","confidence":"High","confidence_rationale":"Tier 2 — epistasis established by multiple genetic and pharmacological approaches with clear pathway positioning","pmids":["11907067"],"is_preprint":false},{"year":2002,"finding":"In NK cells, IL-2 activates a Syk → PI3K → Rac1 → Akt survival cascade: kinase-deficient Syk or Syk inhibitor markedly suppresses IL-2-stimulated PI3K and Akt activation; constitutively active PI3K reverses Syk-impaired Akt activation; dominant-negative Rac1 blocks PI3K-induced Akt activation, while constitutively active Rac1 rescues Akt even in PI3K-impaired cells.","method":"Dominant-negative Syk, piceatannol inhibition, constitutively active/dominant-negative PI3K and Rac1 constructs, Akt phosphorylation assay, cell viability assay","journal":"Blood","confidence":"High","confidence_rationale":"Tier 2 — epistasis established by multiple gain/loss-of-function constructs in a defined signaling cascade","pmids":["12393431"],"is_preprint":false},{"year":1997,"finding":"Pyk2 tyrosine phosphorylation and activation following FcεRI aggregation is downstream of Syk: loss of Syk activity abolishes FcεRI-induced Pyk2 phosphorylation; in contrast, G-protein-coupled receptor-induced Pyk2 phosphorylation is Syk-independent.","method":"FcεRI aggregation assay, Syk-deficient cell analysis, Pyk2 kinase activity assay, pharmacological dissection","journal":"The Journal of biological chemistry","confidence":"Medium","confidence_rationale":"Tier 2 — epistasis with Syk-deficient cells and kinase activity assay, single lab","pmids":["9405454"],"is_preprint":false},{"year":2001,"finding":"CrkL acts as an adapter linking Wiskott-Aldrich syndrome protein (WASP) and Syk: CrkL binds WASP through its SH3 domain and co-precipitates kinase-active Syk; both SH2 and SH3 domains of CrkL are involved in Syk binding; WASP, CrkL, Syk, and Hic-5 are incorporated into the platelet cytoskeleton after aggregation.","method":"Anti-CrkL immunoprecipitation, GST-fusion pulldown, in vitro kinase assay, platelet aggregation cytoskeletal fractionation","journal":"Blood","confidence":"Medium","confidence_rationale":"Tier 2 — reciprocal pulldowns plus in vitro kinase activity, single lab","pmids":["11313252"],"is_preprint":false},{"year":2008,"finding":"Dectin-1 signaling through Syk is required for collaborative cytokine production with TLR2, TLR4, TLR5, TLR7, and TLR9 in macrophages; deficiency of either Syk or the TLR adaptor MyD88 abolishes collaborative responses; Syk/TLR collaboration results in sustained IκB degradation and enhanced NFκB nuclear translocation.","method":"Syk-deficient macrophages, MyD88-deficient macrophages, NFκB nuclear translocation assay, IκB degradation assay, cytokine measurement","journal":"European journal of immunology","confidence":"High","confidence_rationale":"Tier 2 — dual genetic deficiency epistasis with defined pathway readout, independently relevant","pmids":["18200499"],"is_preprint":false},{"year":2000,"finding":"Syk suppresses malignant growth and metastasis in breast cancer cells: reintroduction of wild-type Syk into Syk-negative breast cancer cells inhibited tumor growth and metastasis in athymic mice, while overexpression of kinase-deficient Syk in Syk-positive cells increased tumor incidence; tumor suppression by Syk is associated with aberrant mitosis and cytokinesis.","method":"Syk cDNA transfection, kinase-deficient Syk overexpression, in vivo xenograft mouse model, microscopic analysis of mitosis/cytokinesis","journal":"Nature","confidence":"High","confidence_rationale":"Tier 2 — gain/loss-of-function with kinase-dead mutant control, validated in vivo, replicated across multiple approaches","pmids":["10963601"],"is_preprint":false},{"year":2005,"finding":"Syk kinase activity is required for endothelial cell proliferation and migration; adenoviral expression of Syk dominant-negative mutants severely impaired proliferation and migration of human umbilical vein endothelial cells; Syk kinase activity is closely linked to ERK activation in this context.","method":"Adenovirus-mediated dominant-negative Syk expression, cell proliferation assay, migration assay, ERK phosphorylation assay","journal":"Biochemical and biophysical research communications","confidence":"Medium","confidence_rationale":"Tier 2 — dominant-negative with defined cellular phenotype, single lab","pmids":["11485328"],"is_preprint":false},{"year":2008,"finding":"In airway epithelial cells, Syk associates with clathrin and is recruited to the plasma membrane upon HRV16-ICAM-1 binding, then redistributes to endosomal structures during internalization; kinase-inactive Syk(K396R) blocks HRV endocytosis; Syk is required for HRV-induced PI3K/Akt activation.","method":"Confocal microscopy, co-immunoprecipitation, kinase-dead mutant (K396R), Syk siRNA knockdown, Akt phosphorylation assay","journal":"Journal of immunology (Baltimore, Md. : 1950)","confidence":"Medium","confidence_rationale":"Tier 2 — direct localization plus kinase-dead mutant plus siRNA with defined functional readout","pmids":["18178826"],"is_preprint":false},{"year":2015,"finding":"Syk is recruited to stress granules through a phosphotyrosine-dependent mechanism and via interaction with Grb7; Syk recruitment promotes autophagosome formation and clearance of stress granules from cells, enhancing cell survival after stress.","method":"Proteomic analysis of Syk-binding partners, co-immunoprecipitation, stress granule induction assays, autophagosome formation assay, Grb7 interaction studies","journal":"The Journal of biological chemistry","confidence":"Medium","confidence_rationale":"Tier 2 — proteomic identification with Co-IP validation and functional stress granule assay, single lab","pmids":["26429917"],"is_preprint":false},{"year":2017,"finding":"In γδT cells, Syk (but not ZAP-70) is essential for γδTCR signal transduction and development of IL-17-producing γδT17 cells; Syk activates the PI3K/Akt pathway upon γδTCR stimulation; mice deficient in PI3K signaling show complete loss of γδT17; RhoH (an adaptor that recruits Syk) is required for γδT17-dependent skin inflammation.","method":"Syk conditional knockout mice, ZAP-70 rescue experiments, PI3K-deficient mice, RhoH-deficient mice, γδTCR stimulation assays","journal":"The Journal of clinical investigation","confidence":"High","confidence_rationale":"Tier 2 — multiple genetic KO models with defined pathway and lineage-specific phenotypes","pmids":["29202478"],"is_preprint":false},{"year":2021,"finding":"STAT1 is activated by Syk downstream of RIG-I/MAVS signaling at early stages of influenza A virus infection, independently of cytokines and JAKs; Syk deletion attenuates STAT1 Tyr-701 phosphorylation and ISG expression in vitro and in vivo; STAT1-Y701F knockin mice also show suppressed antiviral responses.","method":"Syk deletion (conditional KO), STAT1-Y701F knockin mice, STAT1 phosphorylation assay, ISG expression analysis, IAV infection model","journal":"Cell reports","confidence":"High","confidence_rationale":"Tier 2 — two independent genetic models (KO and knockin) with defined pathway readout","pmids":["33472080"],"is_preprint":false},{"year":2022,"finding":"TREM2-DAP12 receptor complex transmits signals through SYK; SYK-deficient microglia cannot encase Aβ plaques; SYK deficiency impairs the PI3K-AKT-GSK-3β-mTOR pathway required for disease-associated microglia (DAM) profile; a parallel SYK-independent DAP10-dependent pathway supports microglial proliferation and prodromal DAM; antibody-mediated activation of CLEC7A (which directly activates SYK) rescues microglial activation in TREM2R47H mice.","method":"SYK conditional KO in microglia, TREM2R47H knock-in mice, PI3K/AKT pathway analysis, Aβ plaque encasement assay, anti-CLEC7A antibody treatment","journal":"Cell","confidence":"High","confidence_rationale":"Tier 2 — multiple genetic models with defined pathway and behavioral readouts, two independent papers in same journal","pmids":["36306735","36257314"],"is_preprint":false},{"year":2011,"finding":"CLEC-2 and Syk in the megakaryocyte/platelet lineage are required for normal brain vascular and lymphatic development; conditional deletion of Syk or CLEC-2 specifically in megakaryocytes/platelets recapitulates the vascular/lymphatic defects; platelets (but not platelet releasate) directly modulate lymphatic endothelial cell migration and intercellular adhesion through CLEC-2 and Syk.","method":"Conditional KO mice (hematopoietic lineage-specific and megakaryocyte/platelet-specific), lymphatic endothelial cell migration/adhesion assays in vitro","journal":"Blood","confidence":"High","confidence_rationale":"Tier 2 — multiple conditional KO models with cell-type-specific phenotypes and in vitro mechanistic follow-up","pmids":["22186994"],"is_preprint":false},{"year":2000,"finding":"CCR5 signaling through MIP-1β activates Syk, which associates with RAFTK (Pyk2); RAFTK acts upstream of Syk (dominant-negative RAFTK suppresses Syk activation; overexpressed RAFTK enhances Syk activity); SHP1 and SHP2 are also activated and associate with Syk and Grb2.","method":"Co-immunoprecipitation, dominant-negative RAFTK expression, kinase activity assays, phosphatase inhibitor experiments","journal":"The Journal of biological chemistry","confidence":"Medium","confidence_rationale":"Tier 3 — Co-IP with dominant-negative epistasis, single lab","pmids":["10747947"],"is_preprint":false},{"year":2005,"finding":"The tyrosine kinase Syk regulates TPL2 (Cot) activation downstream of TNF-α: Syk inhibition or Syk deficiency blocks Tpl2-dependent ERK activation; Syk acts downstream of RIP1 and TRAF2 in the TNFR1 pathway but Tpl2 cannot be activated by RIP1/TRAF2 alone without Syk.","method":"Genetic Syk deficiency, pharmacological Syk inhibition, overexpression epistasis (RIP1, TRAF2), kinase activity assays","journal":"The Journal of biological chemistry","confidence":"Medium","confidence_rationale":"Tier 2 — genetic and biochemical epistasis, single lab","pmids":["16291755"],"is_preprint":false},{"year":2014,"finding":"Pharmacological inhibition or siRNA knockdown of Syk reduces Aβ production and increases Aβ clearance across the blood-brain barrier; Syk inhibition induces increased phosphorylation of GSK-3β Ser-9 (inhibitory) via PKA activation, reducing GSK-3β-dependent Tau phosphorylation.","method":"Syk pharmacological inhibitors, siRNA knockdown, in vivo transgenic mouse models (Aβ overexpression and Tau P301S), GSK-3β Ser-9 phosphorylation assay, PKA activity measurement","journal":"The Journal of biological chemistry","confidence":"Medium","confidence_rationale":"Tier 2 — pharmacological and genetic KD with mechanistic pathway readout in vivo and in vitro","pmids":["25331948"],"is_preprint":false},{"year":2019,"finding":"SYK inhibition increases autophagic Tau degradation without affecting Tau production; SYK acts upstream of the mTOR pathway, and SYK inhibition/knockdown decreases mTOR pathway activation and increases autophagy flux; chronic SYK inhibition in a tauopathy mouse model reduces Tau accumulation, neuroinflammation, neuronal/synaptic loss, and reverses defective autophagy.","method":"SYK pharmacological inhibition, shRNA knockdown, mTOR pathway analysis, autophagy flux assay, tauopathy mouse model","journal":"The Journal of biological chemistry","confidence":"Medium","confidence_rationale":"Tier 2 — pharmacological and genetic approaches with mechanistic pathway analysis in vitro and in vivo","pmids":["31324720"],"is_preprint":false},{"year":2011,"finding":"Alternative splicing of SYK regulates mitosis and cell survival; modulating SYK splicing pattern impairs cell-cycle progression and anchorage-independent growth in cancer cells; EGF exposure promotes the pro-survival SYK isoform associated with cancer tissues.","method":"Splicing modulation by antisense oligonucleotides/splicing factors, cell growth/viability/apoptosis assays, anchorage-independent growth assay","journal":"Nature structural & molecular biology","confidence":"Medium","confidence_rationale":"Tier 2 — direct splicing modulation with functional cellular phenotype, single lab","pmids":["21552259"],"is_preprint":false},{"year":2021,"finding":"In B cells, SYK mediates negative selection of autoreactive and premalignant clones; when ZAP-70 is aberrantly expressed in B cells, it competes with SYK at the BCR signalosome, redirecting SYK from NFAT-dependent negative selection to tonic PI3K signaling and promoting survival; conditional Zap70 expression accelerates B cell malignancy and compromises negative selection.","method":"Conditional Zap70 knock-in mice, SYK genetic deletion, BCR signaling assays (NFAT vs PI3K), B-ALL and B-CLL mouse models","journal":"Molecular cell","confidence":"High","confidence_rationale":"Tier 2 — multiple genetic mouse models with defined signaling and B cell selection phenotypes","pmids":["33878293"],"is_preprint":false},{"year":2022,"finding":"Amyloid-β activates the NLRP3 inflammasome in microglia by activating Syk and inhibiting AMPK; inhibited AMPK causes metabolic dysregulation, mitochondrial fragmentation, and ROS formation leading to NLRP3 activation; Syk thus acts upstream of the AMPK-NLRP3 axis.","method":"Syk inhibition, AMPK pathway analysis, ROS measurement, NLRP3 inflammasome activation assay, mitochondrial morphology analysis","journal":"Aging cell","confidence":"Medium","confidence_rationale":"Tier 2 — pharmacological epistasis with defined pathway readout, single lab","pmids":["35474599"],"is_preprint":false},{"year":2013,"finding":"Syk activation induces Blimp-1 expression in B cells, which suppresses Bcl-2 and limits B cell expansion; constitutive Syk activity (via TEL-Syk fusion) drives plasma cell differentiation rather than transformation; combined Syk activation with Bcl-2 transgene leads to plasma cell expansion.","method":"Inducible TEL-Syk knock-in mouse model, Bcl-2 transgene, flow cytometry, gene expression analysis","journal":"Oncogene","confidence":"Medium","confidence_rationale":"Tier 2 — inducible genetic model with defined downstream transcriptional pathway","pmids":["23955076"],"is_preprint":false},{"year":2010,"finding":"Syk is involved in CD40 signaling and is synergistically activated by BCR/CD40 co-stimulation; CD40 alone activates BLNK, Btk, and Vav-2 downstream of Syk, and enhances BCR-induced complex formation of Vav-2, Btk, BLNK, and PLCγ2, leading to ERK, p38, Akt, and NFκB activation.","method":"Co-immunoprecipitation, kinase activity assay, B cell stimulation with anti-CD40 and anti-IgM, Syk inhibitor","journal":"Immunobiology","confidence":"Medium","confidence_rationale":"Tier 3 — Co-IP and pathway analysis, single lab","pmids":["21074890"],"is_preprint":false},{"year":2024,"finding":"PCSK9 binds to CAP1 (adenylyl cyclase-associated protein 1) on macrophages, and this interaction activates Syk and PKCδ as key mediators of inflammation; serum PCSK9 levels positively correlate with Syk, PKCδ, and p65 phosphorylation in human PBMCs; CAP1-Fc fusion protein mitigates PCSK9-mediated SYK signaling.","method":"Co-immunoprecipitation, CAP1 knockdown, kinase phosphorylation assays, LDL receptor KO mouse model, human PBMC correlation studies","journal":"Nature communications","confidence":"Medium","confidence_rationale":"Tier 2 — Co-IP with genetic KO and human validation, single lab","pmids":["38555386"],"is_preprint":false},{"year":2015,"finding":"CD59 crosslinking on erythrocytes induces Syk-dependent phosphorylation of Band 3 and echinocyte morphology; Syk is required for FasL release; FasL-dependent RIP1 phosphorylation combined with membrane pore formation executes necroptosis through RIP3.","method":"CD59 crosslinking, Syk inhibition, Band 3 phosphorylation assay, FasL measurement, RIP1/RIP3 phosphorylation assay, morphological analysis","journal":"Cell death & disease","confidence":"Medium","confidence_rationale":"Tier 2 — pharmacological Syk inhibition with defined pathway epistasis in a specific cell type","pmids":["26018734"],"is_preprint":false},{"year":2016,"finding":"CEACAM3 engagement by Moraxella catarrhalis UspA1 induces NF-κB activation via Syk and the CARD9 pathway in granulocytes; this signaling is dependent on phosphorylation of the CEACAM3 ITAM-like motif and triggers degranulation, ROS production, and chemokine secretion.","method":"Syk inhibitor, siRNA, luciferase NF-κB reporter, chromatin immunoprecipitation, CEACAM3 ITAM phosphorylation assay, granulocyte infection model","journal":"Cellular microbiology","confidence":"Medium","confidence_rationale":"Tier 2 — pharmacological and genetic approaches with defined pathway readout","pmids":["27038042"],"is_preprint":false}],"current_model":"SYK is a cytoplasmic non-receptor tyrosine kinase that is recruited to phosphorylated immunoreceptor tyrosine-based activation motifs (ITAMs) via its tandem SH2 domains, whereupon it is primed by ppITAM binding and then fully activated by LYN-mediated phosphorylation of the SH2-kinase linker (Tyr-348/352) followed by activation-loop autophosphorylation; activated SYK propagates signals to PI3K-AKT, PLCγ, BLNK-BTK, RhoA/Vav, CARD9-NFκB, and mTOR pathways, regulates phagocytosis, cytoskeletal reorganization, B cell and γδT cell development, microglial phagocytosis, and vascular integrity, and its activity is tightly controlled by E3 ligase Cbl- and TRIM31-mediated ubiquitination, USP10-dependent deubiquitination, and proteasomal degradation, while it also functions as a tumor suppressor in epithelial cells by restraining mitosis and EGFR signaling."},"narrative":{"teleology":[{"year":1995,"claim":"Establishing that SYK and ZAP-70 are functionally interchangeable at the BCR defined SYK as the canonical ITAM-proximal kinase in B cells, answering whether SH2-domain-containing kinases could substitute for one another at immunoreceptors.","evidence":"Reconstitution of Syk-deficient B cells with ZAP-70; direct binding assays to phosphorylated Igα/Igβ","pmids":["7538440"],"confidence":"High","gaps":["Whether SYK and ZAP-70 differ in substrate selectivity was not resolved","Structural basis for functional equivalence was unknown"]},{"year":1996,"claim":"Demonstrating that clustered SYK kinase domains alone trigger phagocytosis and actin redistribution established that SYK catalytic activity is both necessary and sufficient for coupling immunoreceptor signals to the cytoskeleton.","evidence":"Chimeric receptor system in COS cells with kinase-dead point mutant; phagocytosis and actin assays","pmids":["8577722"],"confidence":"High","gaps":["Downstream cytoskeletal effectors were not identified","Whether the SH2 domains modulate phagocytic efficiency in vivo was untested"]},{"year":2000,"claim":"Showing that SYK reintroduction suppresses breast cancer growth and metastasis while kinase-dead SYK promotes tumorigenesis revealed an unexpected tumor-suppressor function linked to mitotic fidelity, broadening SYK's role beyond immune cells.","evidence":"Gain- and loss-of-function in breast cancer xenografts with kinase-dead control; mitosis/cytokinesis analysis","pmids":["10963601"],"confidence":"High","gaps":["The mitotic substrate(s) of SYK were not identified","Mechanism of SYK silencing in tumors was unknown"]},{"year":2001,"claim":"Identifying BLNK as the scaffold that couples SYK to BTK phosphorylation resolved how SYK propagates BCR signals to downstream effectors and explained why BLNK deficiency phenocopies SYK deficiency in B cells.","evidence":"Reconstitution system plus analysis of BLNK-deficient and Syk-deficient primary B cells","pmids":["11226282"],"confidence":"High","gaps":["Whether additional scaffolds operate in parallel was unclear","Stoichiometry of the SYK–BLNK–BTK complex was not determined"]},{"year":2001,"claim":"Demonstrating phosphotyrosine-independent binding of SYK tandem SH2 domains to the integrin β3 cytoplasmic tail extended SYK signaling beyond classical ITAMs to integrins, explaining SYK's role in adhesion-dependent lamellipodia formation.","evidence":"Co-IP, β3-tail pulldown, β3-759X deletion mutant; adhesion and lamellipodia assays","pmids":["11719224"],"confidence":"High","gaps":["Structural basis for phosphotyrosine-independent binding was not resolved","Whether this mode of activation occurs in vivo in platelets was not shown"]},{"year":2002,"claim":"Epistasis experiments in NK cells placed SYK upstream of PI3K in DAP12-mediated cytotoxicity and IL-2 survival signaling, defining the SYK→PI3K→Rac1→AKT axis as a core cascade in innate lymphocytes.","evidence":"Dominant-negative SYK, pharmacological inhibition, constitutively active PI3K/Rac1 rescue in NK cells","pmids":["11907067","12393431"],"confidence":"High","gaps":["Direct phosphorylation of PI3K subunits by SYK was not demonstrated","Contribution of other kinases to PI3K activation was not excluded"]},{"year":2006,"claim":"Showing that SYK is required for complement receptor CR3-mediated phagocytosis and RhoA/Vav activation defined a second phagocytic receptor pathway dependent on SYK, paralleling the Fcγ receptor pathway.","evidence":"SYK siRNA and dominant-negative SYK in HL60 cells; CR3-dependent zymosan uptake and RhoA/Vav phosphorylation","pmids":["16449524"],"confidence":"High","gaps":["Whether SYK directly phosphorylates Vav or acts through intermediates was unresolved"]},{"year":2008,"claim":"Demonstrating that Dectin-1/SYK cooperates with multiple TLRs for sustained NF-κB activation established SYK as an integrator of innate pattern-recognition signals beyond single-receptor pathways.","evidence":"Syk-deficient and MyD88-deficient macrophages; IκB degradation and NF-κB translocation assays","pmids":["18200499"],"confidence":"High","gaps":["Molecular mechanism of TLR–SYK convergence on NF-κB was not identified","Whether CARD9 mediates all SYK-dependent NF-κB in this context was untested"]},{"year":2010,"claim":"Resolving the phosphorylation hierarchy — Lyn exclusively phosphorylates Tyr-346 while other sites are dual Lyn/autophosphorylation targets — and identifying C-terminal tyrosines (Tyr-623/624/625) as regulators of kinase activity and ITAM binding provided a detailed activation map of SYK.","evidence":"Selective kinase inhibitors, kinase-dead SYK, Lyn siRNA in mast cells; C-terminal tyrosine mutagenesis with reconstitution in Syk-deficient mast cells","pmids":["20828828","20554527"],"confidence":"High","gaps":["The phosphatase(s) that dephosphorylate each specific site were not identified","Structural consequence of C-terminal tyrosine phosphorylation was not determined"]},{"year":2010,"claim":"Determining that CLEC-2 hemITAM dimers recruit SYK in a 2:1 stoichiometry established an alternative mode of SYK engagement distinct from the dual-ITAM model.","evidence":"SPR, peptide pulldown, tryptophan fluorescence, cross-linking, EM with CLEC-2 tail peptides","pmids":["20154219"],"confidence":"High","gaps":["Whether hemITAM-bound SYK achieves equivalent catalytic output to ppITAM-bound SYK was unknown"]},{"year":2012,"claim":"The crystal structure of full-length autoinhibited SYK showed that ppITAM binding allosterically remodels the ATP-binding site, providing the first structural framework for the SYK activation mechanism.","evidence":"X-ray crystallography of full-length wild-type and Y348F/Y352F SYK with AMP-PNP; SPR, ITC, autophosphorylation assays","pmids":["23154170"],"confidence":"High","gaps":["Structure of fully activated (linker-phosphorylated) SYK was not obtained","Dynamics of conformational change in membranes were not captured"]},{"year":2019,"claim":"Demonstrating that ppITAM binding alone is insufficient to fully activate monomeric SYK and that sequential LYN-mediated Tyr-352→Tyr-348 phosphorylation is required resolved a longstanding question about the obligatory role of Src-family kinase priming.","evidence":"In vitro kinase assay with monomeric untagged recombinant SYK; phosphoproteomics","pmids":["30923129"],"confidence":"High","gaps":["Whether this two-step mechanism operates identically across all ITAM-bearing receptors was not tested"]},{"year":2020,"claim":"Identifying Cbl-mediated SYK degradation as a gatekeeper of germinal center B cell fate — attenuating BCR signal intensity to favor dark-zone recycling over plasma cell differentiation — connected SYK protein turnover to adaptive immune output.","evidence":"Mouse model defective in Cbl-mediated SYK degradation; Kras/ERK and PI3K/Foxo1 pathway analysis; GC B cell flow cytometry","pmids":["31873727"],"confidence":"Medium","gaps":["Specific ubiquitin linkage type on SYK by Cbl was not defined","Whether USP10 counteracts Cbl in GC B cells was not tested"]},{"year":2021,"claim":"Discovery that TRIM31 catalyzes K27-linked polyubiquitination of SYK at Lys-375/517 to promote its membrane translocation and shield it from SHP-1 revealed a positive regulatory ubiquitination pathway distinct from Cbl-mediated degradative ubiquitination.","evidence":"Reconstituted ubiquitination assay, K375/517 mutagenesis, Trim31−/− mice, Candida infection model","pmids":["34362877"],"confidence":"High","gaps":["Whether other E3 ligases also catalyze non-degradative SYK ubiquitination is unknown","Structural basis for K27-linked ubiquitin recognition by downstream effectors was not determined"]},{"year":2022,"claim":"Conditional SYK deletion in microglia ablated TREM2-dependent plaque encasement and the PI3K–AKT–mTOR axis required for the disease-associated microglia program, positioning SYK as an essential transducer in neurodegeneration-associated microglial activation.","evidence":"SYK conditional KO in microglia, TREM2R47H knock-in mice, anti-CLEC7A antibody rescue, Aβ plaque assays","pmids":["36306735","36257314"],"confidence":"High","gaps":["Whether SYK inhibition is therapeutically beneficial or detrimental in Alzheimer's disease is unresolved","SYK substrates specific to microglia were not catalogued"]},{"year":null,"claim":"The structural basis for full SYK activation in the membrane context (linker-phosphorylated, ITAM-bound), the complete inventory of direct SYK substrates across cell types, and whether SYK's tumor-suppressor and neuroinflammatory roles can be therapeutically separated remain open questions.","evidence":"","pmids":[],"confidence":"Low","gaps":["No structure of membrane-associated, fully activated SYK exists","Comprehensive substrate identification across cell types is lacking","Therapeutic window for SYK modulation in neurodegeneration versus immunity is undefined"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0140096","term_label":"catalytic activity, acting on a protein","supporting_discovery_ids":[1,2,5,6,7]},{"term_id":"GO:0098772","term_label":"molecular function regulator activity","supporting_discovery_ids":[23,36]}],"localization":[{"term_id":"GO:0005829","term_label":"cytosol","supporting_discovery_ids":[1,16]},{"term_id":"GO:0005886","term_label":"plasma membrane","supporting_discovery_ids":[0,3,12,25]},{"term_id":"GO:0005634","term_label":"nucleus","supporting_discovery_ids":[16]},{"term_id":"GO:0005815","term_label":"microtubule organizing center","supporting_discovery_ids":[17]},{"term_id":"GO:0005768","term_label":"endosome","supporting_discovery_ids":[25]}],"pathway":[{"term_id":"R-HSA-168256","term_label":"Immune System","supporting_discovery_ids":[1,2,8,9,18,22,27,29,42]},{"term_id":"R-HSA-162582","term_label":"Signal Transduction","supporting_discovery_ids":[5,18,19,28,29,40]},{"term_id":"R-HSA-109582","term_label":"Hemostasis","supporting_discovery_ids":[0,3,30]},{"term_id":"R-HSA-5357801","term_label":"Programmed Cell Death","supporting_discovery_ids":[23,41]},{"term_id":"R-HSA-1266738","term_label":"Developmental Biology","supporting_discovery_ids":[27,30]},{"term_id":"R-HSA-9612973","term_label":"Autophagy","supporting_discovery_ids":[26,34]}],"complexes":[],"partners":["LYN","BLNK","BTK","CLEC1B","CBL","TRIM31","USP10","TREM2"],"other_free_text":[]},"mechanistic_narrative":"SYK is a cytoplasmic non-receptor tyrosine kinase that serves as a central signal-transducing hub downstream of immunoreceptor tyrosine-based activation motif (ITAM)-containing receptors, integrin receptors, and C-type lectins, coupling receptor engagement to phagocytosis, cytoskeletal reorganization, inflammatory cytokine production, and lymphocyte development. Full-length crystal structures reveal an autoinhibited conformation relieved by ppITAM binding to the tandem SH2 domains, which primes SYK for LYN-mediated phosphorylation of linker tyrosines Tyr-348/352 and subsequent activation-loop autophosphorylation [PMID:23154170, PMID:30923129]. Activated SYK phosphorylates BLNK to scaffold BTK activation, signals through PI3K–AKT–mTOR and CARD9–NF-κB axes, drives TREM2-dependent microglial plaque encasement, and is required for γδT17 cell development and complement-mediated phagocytosis [PMID:11226282, PMID:36306735, PMID:29202478, PMID:16449524]. SYK protein levels are regulated by Cbl-mediated and TRIM31-mediated ubiquitination and USP10-dependent deubiquitination, and SYK functions as a tumor suppressor in breast epithelial cells by enforcing proper mitosis [PMID:34362877, PMID:31873727, PMID:10963601]."},"prefetch_data":{"uniprot":{"accession":"P43405","full_name":"Tyrosine-protein kinase SYK","aliases":["Spleen tyrosine kinase","p72-Syk"],"length_aa":635,"mass_kda":72.1,"function":"Non-receptor tyrosine kinase which mediates signal transduction downstream of a variety of transmembrane receptors including classical immunoreceptors like the B-cell receptor (BCR). Regulates several biological processes including innate and adaptive immunity, cell adhesion, osteoclast maturation, platelet activation and vascular development (PubMed:12387735, PubMed:33782605). Assembles into signaling complexes with activated receptors at the plasma membrane via interaction between its SH2 domains and the receptor tyrosine-phosphorylated ITAM domains. The association with the receptor can also be indirect and mediated by adapter proteins containing ITAM or partial hemITAM domains. The phosphorylation of the ITAM domains is generally mediated by SRC subfamily kinases upon engagement of the receptor. More rarely signal transduction via SYK could be ITAM-independent. Direct downstream effectors phosphorylated by SYK include DEPTOR, VAV1, PLCG1, PI-3-kinase, LCP2 and BLNK (PubMed:12456653, PubMed:15388330, PubMed:34634301, PubMed:8657103). Initially identified as essential in B-cell receptor (BCR) signaling, it is necessary for the maturation of B-cells most probably at the pro-B to pre-B transition (PubMed:12456653). Activated upon BCR engagement, it phosphorylates and activates BLNK an adapter linking the activated BCR to downstream signaling adapters and effectors. It also phosphorylates and activates PLCG1 and the PKC signaling pathway. It also phosphorylates BTK and regulates its activity in B-cell antigen receptor (BCR)-coupled signaling. In addition to its function downstream of BCR also plays a role in T-cell receptor signaling. Also plays a crucial role in the innate immune response to fungal, bacterial and viral pathogens. It is for instance activated by the membrane lectin CLEC7A. Upon stimulation by fungal proteins, CLEC7A together with SYK activates immune cells inducing the production of ROS. Also activates the inflammasome and NF-kappa-B-mediated transcription of chemokines and cytokines in presence of pathogens. Regulates neutrophil degranulation and phagocytosis through activation of the MAPK signaling cascade (By similarity). Required for the stimulation of neutrophil phagocytosis by IL15 (PubMed:15123770). Also mediates the activation of dendritic cells by cell necrosis stimuli. Also involved in mast cells activation. Involved in interleukin-3/IL3-mediated signaling pathway in basophils (By similarity). Also functions downstream of receptors mediating cell adhesion (PubMed:12387735). Relays for instance, integrin-mediated neutrophils and macrophages activation and P-selectin receptor/SELPG-mediated recruitment of leukocytes to inflammatory loci. Also plays a role in non-immune processes. It is for instance involved in vascular development where it may regulate blood and lymphatic vascular separation. It is also required for osteoclast development and function. Functions in the activation of platelets by collagen, mediating PLCG2 phosphorylation and activation. May be coupled to the collagen receptor by the ITAM domain-containing FCER1G. Also activated by the membrane lectin CLEC1B that is required for activation of platelets by PDPN/podoplanin. Involved in platelet adhesion being activated by ITGB3 engaged by fibrinogen. Together with CEACAM20, enhances production of the cytokine CXCL8/IL-8 via the NFKB pathway and may thus have a role in the intestinal immune response (By similarity)","subcellular_location":"Cell membrane; Cytoplasm, cytosol","url":"https://www.uniprot.org/uniprotkb/P43405/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/SYK","classification":"Not Classified","n_dependent_lines":24,"n_total_lines":1208,"dependency_fraction":0.019867549668874173},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/SYK","total_profiled":1310},"omim":[{"mim_id":"620484","title":"THROMBOCYTOPENIA 10; THC10","url":"https://www.omim.org/entry/620484"},{"mim_id":"619622","title":"LYMPHOCYTE TRANSMEMBRANE ADAPTOR 1; LAX1","url":"https://www.omim.org/entry/619622"},{"mim_id":"619381","title":"IMMUNODEFICIENCY 82 WITH SYSTEMIC INFLAMMATION; IMD82","url":"https://www.omim.org/entry/619381"},{"mim_id":"619374","title":"IMMUNODEFICIENCY 81; IMD81","url":"https://www.omim.org/entry/619374"},{"mim_id":"618814","title":"KILLER CELL LECTIN-LIKE RECEPTOR F2; KLRF2","url":"https://www.omim.org/entry/618814"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Approved","locations":[{"location":"Plasma membrane","reliability":"Approved"},{"location":"Cytosol","reliability":"Approved"},{"location":"Vesicles","reliability":"Additional"}],"tissue_specificity":"Tissue enhanced","tissue_distribution":"Detected in many","driving_tissues":[{"tissue":"lymphoid tissue","ntpm":69.1},{"tissue":"parathyroid gland","ntpm":82.3}],"url":"https://www.proteinatlas.org/search/SYK"},"hgnc":{"alias_symbol":[],"prev_symbol":[]},"alphafold":{"accession":"P43405","domains":[{"cath_id":"3.30.505.10","chopping":"2-114","consensus_level":"high","plddt":89.7478,"start":2,"end":114},{"cath_id":"3.30.505.10","chopping":"120-257","consensus_level":"medium","plddt":90.8979,"start":120,"end":257},{"cath_id":"3.30.200.20","chopping":"337-448","consensus_level":"medium","plddt":89.6797,"start":337,"end":448},{"cath_id":"1.10.510.10","chopping":"455-524_533-632","consensus_level":"medium","plddt":93.5291,"start":455,"end":632}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/P43405","model_url":"https://alphafold.ebi.ac.uk/files/AF-P43405-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-P43405-F1-predicted_aligned_error_v6.png","plddt_mean":84.0},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=SYK","jax_strain_url":"https://www.jax.org/strain/search?query=SYK"},"sequence":{"accession":"P43405","fasta_url":"https://rest.uniprot.org/uniprotkb/P43405.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/P43405/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/P43405"}},"corpus_meta":[{"pmid":"20467426","id":"PMC_20467426","title":"The SYK tyrosine kinase: a crucial player in diverse biological functions.","date":"2010","source":"Nature reviews. 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\"Co-immunoprecipitation, pulldown with β3 cytoplasmic tail, cell adhesion assay with mutant integrin (β3-759X), kinase activity assay\",\n      \"journal\": \"Current biology : CB\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — reciprocal binding assays plus functional mutagenesis with defined cellular phenotype\",\n      \"pmids\": [\"11719224\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1996,\n      \"finding\": \"Clustered Syk kinase domains are sufficient to autonomously trigger phagocytosis and filamentous actin redistribution in COS cells; a catalytic-domain point mutation abolishes this activity, and the kinase domain alone is sufficient for cytoskeletal coupling.\",\n      \"method\": \"Chimeric transmembrane receptor expression in COS cells, phagocytosis assay, actin redistribution assay, catalytic-dead point mutant\",\n      \"journal\": \"Proceedings of the National Academy of Sciences of the United States of America\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 — reconstitution with mutagenesis establishing catalytic requirement\",\n      \"pmids\": [\"8577722\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2001,\n      \"finding\": \"BLNK mediates Syk-dependent Btk activation: Syk phosphorylates Btk on Tyr-551 via BLNK as a scaffold, requiring the Btk-SH2 domain interaction with BLNK; BCR-induced Btk phosphorylation and activation are significantly reduced in both BLNK-deficient and Syk-deficient B cells.\",\n      \"method\": \"Reconstitution cell system co-expression, in vitro phosphorylation assay, BLNK-deficient and Syk-deficient B cell analysis\",\n      \"journal\": \"Proceedings of the National Academy of Sciences of the United States of America\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 — reconstitution assay with genetic validation in deficient cells\",\n      \"pmids\": [\"11226282\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2010,\n      \"finding\": \"CLEC-2 activates Syk through receptor dimerization: the single YxxL hemITAM in the CLEC-2 cytosolic tail, when phosphorylated, recruits Syk tandem SH2 domains in a 2:1 (CLEC-2:Syk) stoichiometry; CLEC-2 exists as a dimer in resting platelets and forms larger complexes upon activation.\",\n      \"method\": \"Peptide pulldown, surface plasmon resonance, quantitative Western blot, tryptophan fluorescence, competition experiments, cross-linking, electron microscopy\",\n      \"journal\": \"Blood\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 — multiple orthogonal biophysical and biochemical methods in a single study\",\n      \"pmids\": [\"20154219\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"Crystal structures of full-length Syk (wild type and Y348F/Y352F mutant) in complex with AMP-PNP reveal an autoinhibited conformation; pITAM binding to the tSH2 domain stimulates in vitro autophosphorylation and confers conformational changes at the ATP-binding site of the kinase domain, consistent with allosteric activation.\",\n      \"method\": \"X-ray crystallography of full-length Syk, surface plasmon resonance, isothermal titration calorimetry, in vitro autophosphorylation assay, mutagenesis (Y348F/Y352F)\",\n      \"journal\": \"Journal of molecular biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 — crystal structure plus multiple orthogonal biochemical methods with mutagenesis\",\n      \"pmids\": [\"23154170\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"SYK activation requires both ppITAM binding (which primes SYK) and LYN-mediated phosphorylation of Tyr-352 then Tyr-348 in the SH2-kinase linker, which then facilitates activation-loop phosphorylation and full SYK activation; ppITAM alone is insufficient to fully activate monomeric untagged SYK.\",\n      \"method\": \"In vitro kinase assay with unphosphorylated and phosphorylated recombinant SYK (monomeric and obligatory-dimeric forms), immunoblot, phosphoproteomics\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 — reconstituted in vitro kinase system with phosphoproteomic site mapping\",\n      \"pmids\": [\"30923129\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2010,\n      \"finding\": \"Syk tyrosine 346 in FcεRI signaling is exclusively phosphorylated by Src family kinases (predominantly Lyn), while tyrosines 317, 342, 519, and 520 are phosphorylated by both Syk auto/trans-phosphorylation and Src family kinases; Lyn knockdown impairs phosphorylation of Syk substrates SLP-76 and LAT but paradoxically sensitizes cells to degranulation by enhancing distal ERK activation.\",\n      \"method\": \"Selective kinase inhibitors, kinase-dead Syk, Lyn siRNA knockdown, site-specific phospho-antibodies in RBL-2H3 and bone marrow-derived mast cells\",\n      \"journal\": \"Molecular immunology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1/2 — multiple orthogonal approaches (pharmacologic inhibition, siRNA, KD mutant) with site-specific readouts\",\n      \"pmids\": [\"20828828\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2010,\n      \"finding\": \"C-terminal tyrosines Tyr-623, Tyr-624, and Tyr-625 of Syk regulate its kinase activity and ITAM binding: mutation of these residues increases basal autophosphorylation and reduces kinase activity toward exogenous substrates, decreases ITAM binding, and impairs FcεRI-induced degranulation, NFAT, NFκB, and MAP kinase activation; Tyr-625 has the dominant role.\",\n      \"method\": \"Site-directed mutagenesis, in vitro kinase assay, ITAM binding assay, degranulation assay, signaling readouts in Syk-deficient mast cells reconstituted with wild-type or mutant Syk\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 — in vitro assay plus mutagenesis with functional cellular reconstitution\",\n      \"pmids\": [\"20554527\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1995,\n      \"finding\": \"ZAP-70 and Syk are functionally homologous: ZAP-70 expression in Syk-deficient B cells reconstitutes BCR function, requiring intact SH2 and catalytic domains; both kinases bind directly to phosphorylated Igα and Igβ subunits with comparable affinities.\",\n      \"method\": \"Reconstitution of Syk-deficient B cells with ZAP-70, direct binding assay to phosphorylated BCR subunits, domain-deletion mutants\",\n      \"journal\": \"Immunity\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 — genetic reconstitution plus direct binding assays\",\n      \"pmids\": [\"7538440\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2006,\n      \"finding\": \"Syk is required for pathogen engulfment in complement-mediated phagocytosis (via CR3): Syk becomes tyrosine-phosphorylated and accumulates around nascent phagosomes during C3bi-opsonized zymosan uptake; Syk-siRNA or dominant-negative Syk impairs engulfment, actin accumulation/depolymerization around phagosomes, and RhoA activation/Vav tyrosine phosphorylation.\",\n      \"method\": \"siRNA knockdown, dominant-negative Syk expression, fluorescence quenching phagocytosis assay, immunofluorescence, tyrosine phosphorylation assay in HL60 cells\",\n      \"journal\": \"Blood\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — multiple orthogonal genetic approaches with defined mechanistic pathway readouts\",\n      \"pmids\": [\"16449524\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"Jedi-1 and MEGF10 signal engulfment of apoptotic neurons through Syk: Syk interacts with the ITAMs of both receptors; ITAM phosphorylation by Src family kinases enhances Syk interaction and activation; ITAM tyrosine mutation or Syk inhibition blocks phagocytosis of microspheres and apoptotic neurons in glial precursor cocultures.\",\n      \"method\": \"Co-immunoprecipitation, ITAM tyrosine mutagenesis, pharmacologic Syk inhibition (BAY 61-3606), Syk siRNA knockdown in mouse embryonic glial precursors, engulfment assay\",\n      \"journal\": \"The Journal of neuroscience : the official journal of the Society for Neuroscience\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — reciprocal Co-IP plus mutagenesis plus genetic KD with defined phagocytic phenotype\",\n      \"pmids\": [\"22993420\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"Retroviral retention induces phosphorylation of conserved tyrosines in tetherin cytoplasmic tail dimers, recruiting Syk; Syk is required for downstream NF-κB activation; tetherin signaling is coupled to cortical actin via RICH2 (ARHGAP44), and a naturally occurring tetherin polymorphism with reduced RICH2 binding shows decreased tetherin phosphorylation and NF-κB activation.\",\n      \"method\": \"Co-immunoprecipitation, phosphorylation assays, NF-κB reporter assay, tetherin polymorphism analysis, retroviral particle retention assay\",\n      \"journal\": \"Cell host & microbe\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — multiple orthogonal methods linking Syk recruitment to functional NF-κB signaling with natural variant validation\",\n      \"pmids\": [\"25211072\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"TRIM31 E3 ligase catalyzes K27-linked polyubiquitination of SYK at Lys-375 and Lys-517, promoting SYK plasma membrane translocation and binding to C-type lectin receptors, and preventing interaction with the phosphatase SHP-1; Trim31-deficient macrophages and dendritic cells show dampened SYK-mediated signaling and impaired cytokine responses to Candida albicans.\",\n      \"method\": \"Co-immunoprecipitation, ubiquitination assay, site-directed mutagenesis (K375/K517), subcellular fractionation, Trim31-/- mouse model, in vitro infection assay\",\n      \"journal\": \"Signal transduction and targeted therapy\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — reconstituted ubiquitination assay with mutagenesis, validated in KO mouse model\",\n      \"pmids\": [\"34362877\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"USP10 is a major deubiquitinase required for SYK protein stabilization; USP10 inhibition induces SYK degradation via the proteasome and kills cells driven by active SYK or oncogenic FLT3.\",\n      \"method\": \"USP10 inhibitor treatment, SYK protein stability assays, cell viability assays, co-immunoprecipitation\",\n      \"journal\": \"British journal of cancer\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — pharmacologic and biochemical evidence, single lab\",\n      \"pmids\": [\"32015510\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2004,\n      \"finding\": \"IgE/FcεRI stimulation of basophils leads to c-Cbl phosphorylation, c-Cbl association with Syk, Syk ubiquitylation, and proteasome-dependent Syk degradation over hours; proteasome inhibition with lactacystin A results in accumulation of high-molecular-weight ubiquitylated Syk species.\",\n      \"method\": \"Immunoprecipitation, immunoblotting, proteasome inhibition (lactacystin A), primary human basophils\",\n      \"journal\": \"The Journal of allergy and clinical immunology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — Co-IP plus pharmacological inhibition establishing ubiquitin-proteasome regulation\",\n      \"pmids\": [\"15577829\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"Cbl-mediated Syk degradation in germinal center B cells attenuates BCR signaling intensity by mitigating Kras/Erk and PI3K/Foxo1 pathways, restraining plasma cell formation and promoting light-zone-to-dark-zone transition.\",\n      \"method\": \"Mouse model defective in Cbl-mediated Syk degradation, gene expression analysis, flow cytometry, signaling pathway analysis\",\n      \"journal\": \"The Journal of experimental medicine\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — genetic mouse model with defined pathway readouts, single lab\",\n      \"pmids\": [\"31873727\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2006,\n      \"finding\": \"Syk shuttles between nuclear and cytoplasmic compartments via an unconventional shuttling sequence at the junction of the catalytic domain and linker B region; BCR engagement causes nuclear exclusion of Syk through protein kinase C activation and new protein synthesis; nuclear exclusion promotes stress-induced caspase-3 activation.\",\n      \"method\": \"Deletion mutant analysis, subcellular fractionation, live-cell imaging, pharmacological inhibitors (PKC), caspase-3 activation assays\",\n      \"journal\": \"Molecular and cellular biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — domain-deletion mapping plus functional consequence in B cells\",\n      \"pmids\": [\"16611990\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2005,\n      \"finding\": \"Syk colocalizes and copurifies with the centrosomal marker γ-tubulin, exhibits catalytic activity within centrosomes, requires intact kinase activity for centrosomal localization, and is degraded via ubiquitinylation/proteasome during mitosis; unrestrained Syk overexpression causes multipolar spindles, supernumerary centrosomes, and mitotic catastrophe.\",\n      \"method\": \"Colocalization by immunofluorescence, centrosome purification/copurification, in vitro kinase assay, DsRed-Syk overexpression, live-cell imaging\",\n      \"journal\": \"Cancer research\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — subcellular fractionation with kinase activity assay and functional overexpression phenotype\",\n      \"pmids\": [\"16322234\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2002,\n      \"finding\": \"In NK cells, Syk acts upstream of PI3K in the DAP12-mediated cytotoxicity pathway: tumor cell ligation induces DAP12 tyrosine phosphorylation and DAP12-Syk association; kinase-deficient Syk or Syk inhibitor blocks PI3K, Rac1, PAK1, MEK, and ERK activation as well as perforin movement and NK cytotoxicity; constitutively active PI3K rescues all downstream events in Syk-impaired cells.\",\n      \"method\": \"Dominant-negative Syk expression, pharmacological inhibition (piceatannol), constitutively active PI3K rescue, co-immunoprecipitation, kinase activity assays, cytotoxicity assays\",\n      \"journal\": \"Journal of immunology (Baltimore, Md. : 1950)\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — epistasis established by multiple genetic and pharmacological approaches with clear pathway positioning\",\n      \"pmids\": [\"11907067\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2002,\n      \"finding\": \"In NK cells, IL-2 activates a Syk → PI3K → Rac1 → Akt survival cascade: kinase-deficient Syk or Syk inhibitor markedly suppresses IL-2-stimulated PI3K and Akt activation; constitutively active PI3K reverses Syk-impaired Akt activation; dominant-negative Rac1 blocks PI3K-induced Akt activation, while constitutively active Rac1 rescues Akt even in PI3K-impaired cells.\",\n      \"method\": \"Dominant-negative Syk, piceatannol inhibition, constitutively active/dominant-negative PI3K and Rac1 constructs, Akt phosphorylation assay, cell viability assay\",\n      \"journal\": \"Blood\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — epistasis established by multiple gain/loss-of-function constructs in a defined signaling cascade\",\n      \"pmids\": [\"12393431\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1997,\n      \"finding\": \"Pyk2 tyrosine phosphorylation and activation following FcεRI aggregation is downstream of Syk: loss of Syk activity abolishes FcεRI-induced Pyk2 phosphorylation; in contrast, G-protein-coupled receptor-induced Pyk2 phosphorylation is Syk-independent.\",\n      \"method\": \"FcεRI aggregation assay, Syk-deficient cell analysis, Pyk2 kinase activity assay, pharmacological dissection\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — epistasis with Syk-deficient cells and kinase activity assay, single lab\",\n      \"pmids\": [\"9405454\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2001,\n      \"finding\": \"CrkL acts as an adapter linking Wiskott-Aldrich syndrome protein (WASP) and Syk: CrkL binds WASP through its SH3 domain and co-precipitates kinase-active Syk; both SH2 and SH3 domains of CrkL are involved in Syk binding; WASP, CrkL, Syk, and Hic-5 are incorporated into the platelet cytoskeleton after aggregation.\",\n      \"method\": \"Anti-CrkL immunoprecipitation, GST-fusion pulldown, in vitro kinase assay, platelet aggregation cytoskeletal fractionation\",\n      \"journal\": \"Blood\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — reciprocal pulldowns plus in vitro kinase activity, single lab\",\n      \"pmids\": [\"11313252\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2008,\n      \"finding\": \"Dectin-1 signaling through Syk is required for collaborative cytokine production with TLR2, TLR4, TLR5, TLR7, and TLR9 in macrophages; deficiency of either Syk or the TLR adaptor MyD88 abolishes collaborative responses; Syk/TLR collaboration results in sustained IκB degradation and enhanced NFκB nuclear translocation.\",\n      \"method\": \"Syk-deficient macrophages, MyD88-deficient macrophages, NFκB nuclear translocation assay, IκB degradation assay, cytokine measurement\",\n      \"journal\": \"European journal of immunology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — dual genetic deficiency epistasis with defined pathway readout, independently relevant\",\n      \"pmids\": [\"18200499\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2000,\n      \"finding\": \"Syk suppresses malignant growth and metastasis in breast cancer cells: reintroduction of wild-type Syk into Syk-negative breast cancer cells inhibited tumor growth and metastasis in athymic mice, while overexpression of kinase-deficient Syk in Syk-positive cells increased tumor incidence; tumor suppression by Syk is associated with aberrant mitosis and cytokinesis.\",\n      \"method\": \"Syk cDNA transfection, kinase-deficient Syk overexpression, in vivo xenograft mouse model, microscopic analysis of mitosis/cytokinesis\",\n      \"journal\": \"Nature\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — gain/loss-of-function with kinase-dead mutant control, validated in vivo, replicated across multiple approaches\",\n      \"pmids\": [\"10963601\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2005,\n      \"finding\": \"Syk kinase activity is required for endothelial cell proliferation and migration; adenoviral expression of Syk dominant-negative mutants severely impaired proliferation and migration of human umbilical vein endothelial cells; Syk kinase activity is closely linked to ERK activation in this context.\",\n      \"method\": \"Adenovirus-mediated dominant-negative Syk expression, cell proliferation assay, migration assay, ERK phosphorylation assay\",\n      \"journal\": \"Biochemical and biophysical research communications\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — dominant-negative with defined cellular phenotype, single lab\",\n      \"pmids\": [\"11485328\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2008,\n      \"finding\": \"In airway epithelial cells, Syk associates with clathrin and is recruited to the plasma membrane upon HRV16-ICAM-1 binding, then redistributes to endosomal structures during internalization; kinase-inactive Syk(K396R) blocks HRV endocytosis; Syk is required for HRV-induced PI3K/Akt activation.\",\n      \"method\": \"Confocal microscopy, co-immunoprecipitation, kinase-dead mutant (K396R), Syk siRNA knockdown, Akt phosphorylation assay\",\n      \"journal\": \"Journal of immunology (Baltimore, Md. : 1950)\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — direct localization plus kinase-dead mutant plus siRNA with defined functional readout\",\n      \"pmids\": [\"18178826\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"Syk is recruited to stress granules through a phosphotyrosine-dependent mechanism and via interaction with Grb7; Syk recruitment promotes autophagosome formation and clearance of stress granules from cells, enhancing cell survival after stress.\",\n      \"method\": \"Proteomic analysis of Syk-binding partners, co-immunoprecipitation, stress granule induction assays, autophagosome formation assay, Grb7 interaction studies\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — proteomic identification with Co-IP validation and functional stress granule assay, single lab\",\n      \"pmids\": [\"26429917\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"In γδT cells, Syk (but not ZAP-70) is essential for γδTCR signal transduction and development of IL-17-producing γδT17 cells; Syk activates the PI3K/Akt pathway upon γδTCR stimulation; mice deficient in PI3K signaling show complete loss of γδT17; RhoH (an adaptor that recruits Syk) is required for γδT17-dependent skin inflammation.\",\n      \"method\": \"Syk conditional knockout mice, ZAP-70 rescue experiments, PI3K-deficient mice, RhoH-deficient mice, γδTCR stimulation assays\",\n      \"journal\": \"The Journal of clinical investigation\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — multiple genetic KO models with defined pathway and lineage-specific phenotypes\",\n      \"pmids\": [\"29202478\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"STAT1 is activated by Syk downstream of RIG-I/MAVS signaling at early stages of influenza A virus infection, independently of cytokines and JAKs; Syk deletion attenuates STAT1 Tyr-701 phosphorylation and ISG expression in vitro and in vivo; STAT1-Y701F knockin mice also show suppressed antiviral responses.\",\n      \"method\": \"Syk deletion (conditional KO), STAT1-Y701F knockin mice, STAT1 phosphorylation assay, ISG expression analysis, IAV infection model\",\n      \"journal\": \"Cell reports\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — two independent genetic models (KO and knockin) with defined pathway readout\",\n      \"pmids\": [\"33472080\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"TREM2-DAP12 receptor complex transmits signals through SYK; SYK-deficient microglia cannot encase Aβ plaques; SYK deficiency impairs the PI3K-AKT-GSK-3β-mTOR pathway required for disease-associated microglia (DAM) profile; a parallel SYK-independent DAP10-dependent pathway supports microglial proliferation and prodromal DAM; antibody-mediated activation of CLEC7A (which directly activates SYK) rescues microglial activation in TREM2R47H mice.\",\n      \"method\": \"SYK conditional KO in microglia, TREM2R47H knock-in mice, PI3K/AKT pathway analysis, Aβ plaque encasement assay, anti-CLEC7A antibody treatment\",\n      \"journal\": \"Cell\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — multiple genetic models with defined pathway and behavioral readouts, two independent papers in same journal\",\n      \"pmids\": [\"36306735\", \"36257314\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2011,\n      \"finding\": \"CLEC-2 and Syk in the megakaryocyte/platelet lineage are required for normal brain vascular and lymphatic development; conditional deletion of Syk or CLEC-2 specifically in megakaryocytes/platelets recapitulates the vascular/lymphatic defects; platelets (but not platelet releasate) directly modulate lymphatic endothelial cell migration and intercellular adhesion through CLEC-2 and Syk.\",\n      \"method\": \"Conditional KO mice (hematopoietic lineage-specific and megakaryocyte/platelet-specific), lymphatic endothelial cell migration/adhesion assays in vitro\",\n      \"journal\": \"Blood\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — multiple conditional KO models with cell-type-specific phenotypes and in vitro mechanistic follow-up\",\n      \"pmids\": [\"22186994\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2000,\n      \"finding\": \"CCR5 signaling through MIP-1β activates Syk, which associates with RAFTK (Pyk2); RAFTK acts upstream of Syk (dominant-negative RAFTK suppresses Syk activation; overexpressed RAFTK enhances Syk activity); SHP1 and SHP2 are also activated and associate with Syk and Grb2.\",\n      \"method\": \"Co-immunoprecipitation, dominant-negative RAFTK expression, kinase activity assays, phosphatase inhibitor experiments\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 — Co-IP with dominant-negative epistasis, single lab\",\n      \"pmids\": [\"10747947\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2005,\n      \"finding\": \"The tyrosine kinase Syk regulates TPL2 (Cot) activation downstream of TNF-α: Syk inhibition or Syk deficiency blocks Tpl2-dependent ERK activation; Syk acts downstream of RIP1 and TRAF2 in the TNFR1 pathway but Tpl2 cannot be activated by RIP1/TRAF2 alone without Syk.\",\n      \"method\": \"Genetic Syk deficiency, pharmacological Syk inhibition, overexpression epistasis (RIP1, TRAF2), kinase activity assays\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — genetic and biochemical epistasis, single lab\",\n      \"pmids\": [\"16291755\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"Pharmacological inhibition or siRNA knockdown of Syk reduces Aβ production and increases Aβ clearance across the blood-brain barrier; Syk inhibition induces increased phosphorylation of GSK-3β Ser-9 (inhibitory) via PKA activation, reducing GSK-3β-dependent Tau phosphorylation.\",\n      \"method\": \"Syk pharmacological inhibitors, siRNA knockdown, in vivo transgenic mouse models (Aβ overexpression and Tau P301S), GSK-3β Ser-9 phosphorylation assay, PKA activity measurement\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — pharmacological and genetic KD with mechanistic pathway readout in vivo and in vitro\",\n      \"pmids\": [\"25331948\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"SYK inhibition increases autophagic Tau degradation without affecting Tau production; SYK acts upstream of the mTOR pathway, and SYK inhibition/knockdown decreases mTOR pathway activation and increases autophagy flux; chronic SYK inhibition in a tauopathy mouse model reduces Tau accumulation, neuroinflammation, neuronal/synaptic loss, and reverses defective autophagy.\",\n      \"method\": \"SYK pharmacological inhibition, shRNA knockdown, mTOR pathway analysis, autophagy flux assay, tauopathy mouse model\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — pharmacological and genetic approaches with mechanistic pathway analysis in vitro and in vivo\",\n      \"pmids\": [\"31324720\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2011,\n      \"finding\": \"Alternative splicing of SYK regulates mitosis and cell survival; modulating SYK splicing pattern impairs cell-cycle progression and anchorage-independent growth in cancer cells; EGF exposure promotes the pro-survival SYK isoform associated with cancer tissues.\",\n      \"method\": \"Splicing modulation by antisense oligonucleotides/splicing factors, cell growth/viability/apoptosis assays, anchorage-independent growth assay\",\n      \"journal\": \"Nature structural & molecular biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — direct splicing modulation with functional cellular phenotype, single lab\",\n      \"pmids\": [\"21552259\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"In B cells, SYK mediates negative selection of autoreactive and premalignant clones; when ZAP-70 is aberrantly expressed in B cells, it competes with SYK at the BCR signalosome, redirecting SYK from NFAT-dependent negative selection to tonic PI3K signaling and promoting survival; conditional Zap70 expression accelerates B cell malignancy and compromises negative selection.\",\n      \"method\": \"Conditional Zap70 knock-in mice, SYK genetic deletion, BCR signaling assays (NFAT vs PI3K), B-ALL and B-CLL mouse models\",\n      \"journal\": \"Molecular cell\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — multiple genetic mouse models with defined signaling and B cell selection phenotypes\",\n      \"pmids\": [\"33878293\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"Amyloid-β activates the NLRP3 inflammasome in microglia by activating Syk and inhibiting AMPK; inhibited AMPK causes metabolic dysregulation, mitochondrial fragmentation, and ROS formation leading to NLRP3 activation; Syk thus acts upstream of the AMPK-NLRP3 axis.\",\n      \"method\": \"Syk inhibition, AMPK pathway analysis, ROS measurement, NLRP3 inflammasome activation assay, mitochondrial morphology analysis\",\n      \"journal\": \"Aging cell\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — pharmacological epistasis with defined pathway readout, single lab\",\n      \"pmids\": [\"35474599\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"Syk activation induces Blimp-1 expression in B cells, which suppresses Bcl-2 and limits B cell expansion; constitutive Syk activity (via TEL-Syk fusion) drives plasma cell differentiation rather than transformation; combined Syk activation with Bcl-2 transgene leads to plasma cell expansion.\",\n      \"method\": \"Inducible TEL-Syk knock-in mouse model, Bcl-2 transgene, flow cytometry, gene expression analysis\",\n      \"journal\": \"Oncogene\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — inducible genetic model with defined downstream transcriptional pathway\",\n      \"pmids\": [\"23955076\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2010,\n      \"finding\": \"Syk is involved in CD40 signaling and is synergistically activated by BCR/CD40 co-stimulation; CD40 alone activates BLNK, Btk, and Vav-2 downstream of Syk, and enhances BCR-induced complex formation of Vav-2, Btk, BLNK, and PLCγ2, leading to ERK, p38, Akt, and NFκB activation.\",\n      \"method\": \"Co-immunoprecipitation, kinase activity assay, B cell stimulation with anti-CD40 and anti-IgM, Syk inhibitor\",\n      \"journal\": \"Immunobiology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 — Co-IP and pathway analysis, single lab\",\n      \"pmids\": [\"21074890\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"PCSK9 binds to CAP1 (adenylyl cyclase-associated protein 1) on macrophages, and this interaction activates Syk and PKCδ as key mediators of inflammation; serum PCSK9 levels positively correlate with Syk, PKCδ, and p65 phosphorylation in human PBMCs; CAP1-Fc fusion protein mitigates PCSK9-mediated SYK signaling.\",\n      \"method\": \"Co-immunoprecipitation, CAP1 knockdown, kinase phosphorylation assays, LDL receptor KO mouse model, human PBMC correlation studies\",\n      \"journal\": \"Nature communications\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — Co-IP with genetic KO and human validation, single lab\",\n      \"pmids\": [\"38555386\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"CD59 crosslinking on erythrocytes induces Syk-dependent phosphorylation of Band 3 and echinocyte morphology; Syk is required for FasL release; FasL-dependent RIP1 phosphorylation combined with membrane pore formation executes necroptosis through RIP3.\",\n      \"method\": \"CD59 crosslinking, Syk inhibition, Band 3 phosphorylation assay, FasL measurement, RIP1/RIP3 phosphorylation assay, morphological analysis\",\n      \"journal\": \"Cell death & disease\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — pharmacological Syk inhibition with defined pathway epistasis in a specific cell type\",\n      \"pmids\": [\"26018734\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"CEACAM3 engagement by Moraxella catarrhalis UspA1 induces NF-κB activation via Syk and the CARD9 pathway in granulocytes; this signaling is dependent on phosphorylation of the CEACAM3 ITAM-like motif and triggers degranulation, ROS production, and chemokine secretion.\",\n      \"method\": \"Syk inhibitor, siRNA, luciferase NF-κB reporter, chromatin immunoprecipitation, CEACAM3 ITAM phosphorylation assay, granulocyte infection model\",\n      \"journal\": \"Cellular microbiology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — pharmacological and genetic approaches with defined pathway readout\",\n      \"pmids\": [\"27038042\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"SYK is a cytoplasmic non-receptor tyrosine kinase that is recruited to phosphorylated immunoreceptor tyrosine-based activation motifs (ITAMs) via its tandem SH2 domains, whereupon it is primed by ppITAM binding and then fully activated by LYN-mediated phosphorylation of the SH2-kinase linker (Tyr-348/352) followed by activation-loop autophosphorylation; activated SYK propagates signals to PI3K-AKT, PLCγ, BLNK-BTK, RhoA/Vav, CARD9-NFκB, and mTOR pathways, regulates phagocytosis, cytoskeletal reorganization, B cell and γδT cell development, microglial phagocytosis, and vascular integrity, and its activity is tightly controlled by E3 ligase Cbl- and TRIM31-mediated ubiquitination, USP10-dependent deubiquitination, and proteasomal degradation, while it also functions as a tumor suppressor in epithelial cells by restraining mitosis and EGFR signaling.\"\n}\n```","stage2_raw":"```json\n{\n  \"mechanistic_narrative\": \"SYK is a cytoplasmic non-receptor tyrosine kinase that serves as a central signal-transducing hub downstream of immunoreceptor tyrosine-based activation motif (ITAM)-containing receptors, integrin receptors, and C-type lectins, coupling receptor engagement to phagocytosis, cytoskeletal reorganization, inflammatory cytokine production, and lymphocyte development. Full-length crystal structures reveal an autoinhibited conformation relieved by ppITAM binding to the tandem SH2 domains, which primes SYK for LYN-mediated phosphorylation of linker tyrosines Tyr-348/352 and subsequent activation-loop autophosphorylation [PMID:23154170, PMID:30923129]. Activated SYK phosphorylates BLNK to scaffold BTK activation, signals through PI3K–AKT–mTOR and CARD9–NF-κB axes, drives TREM2-dependent microglial plaque encasement, and is required for γδT17 cell development and complement-mediated phagocytosis [PMID:11226282, PMID:36306735, PMID:29202478, PMID:16449524]. SYK protein levels are regulated by Cbl-mediated and TRIM31-mediated ubiquitination and USP10-dependent deubiquitination, and SYK functions as a tumor suppressor in breast epithelial cells by enforcing proper mitosis [PMID:34362877, PMID:31873727, PMID:10963601].\",\n  \"teleology\": [\n    {\n      \"year\": 1995,\n      \"claim\": \"Establishing that SYK and ZAP-70 are functionally interchangeable at the BCR defined SYK as the canonical ITAM-proximal kinase in B cells, answering whether SH2-domain-containing kinases could substitute for one another at immunoreceptors.\",\n      \"evidence\": \"Reconstitution of Syk-deficient B cells with ZAP-70; direct binding assays to phosphorylated Igα/Igβ\",\n      \"pmids\": [\"7538440\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Whether SYK and ZAP-70 differ in substrate selectivity was not resolved\", \"Structural basis for functional equivalence was unknown\"]\n    },\n    {\n      \"year\": 1996,\n      \"claim\": \"Demonstrating that clustered SYK kinase domains alone trigger phagocytosis and actin redistribution established that SYK catalytic activity is both necessary and sufficient for coupling immunoreceptor signals to the cytoskeleton.\",\n      \"evidence\": \"Chimeric receptor system in COS cells with kinase-dead point mutant; phagocytosis and actin assays\",\n      \"pmids\": [\"8577722\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Downstream cytoskeletal effectors were not identified\", \"Whether the SH2 domains modulate phagocytic efficiency in vivo was untested\"]\n    },\n    {\n      \"year\": 2000,\n      \"claim\": \"Showing that SYK reintroduction suppresses breast cancer growth and metastasis while kinase-dead SYK promotes tumorigenesis revealed an unexpected tumor-suppressor function linked to mitotic fidelity, broadening SYK's role beyond immune cells.\",\n      \"evidence\": \"Gain- and loss-of-function in breast cancer xenografts with kinase-dead control; mitosis/cytokinesis analysis\",\n      \"pmids\": [\"10963601\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"The mitotic substrate(s) of SYK were not identified\", \"Mechanism of SYK silencing in tumors was unknown\"]\n    },\n    {\n      \"year\": 2001,\n      \"claim\": \"Identifying BLNK as the scaffold that couples SYK to BTK phosphorylation resolved how SYK propagates BCR signals to downstream effectors and explained why BLNK deficiency phenocopies SYK deficiency in B cells.\",\n      \"evidence\": \"Reconstitution system plus analysis of BLNK-deficient and Syk-deficient primary B cells\",\n      \"pmids\": [\"11226282\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Whether additional scaffolds operate in parallel was unclear\", \"Stoichiometry of the SYK–BLNK–BTK complex was not determined\"]\n    },\n    {\n      \"year\": 2001,\n      \"claim\": \"Demonstrating phosphotyrosine-independent binding of SYK tandem SH2 domains to the integrin β3 cytoplasmic tail extended SYK signaling beyond classical ITAMs to integrins, explaining SYK's role in adhesion-dependent lamellipodia formation.\",\n      \"evidence\": \"Co-IP, β3-tail pulldown, β3-759X deletion mutant; adhesion and lamellipodia assays\",\n      \"pmids\": [\"11719224\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Structural basis for phosphotyrosine-independent binding was not resolved\", \"Whether this mode of activation occurs in vivo in platelets was not shown\"]\n    },\n    {\n      \"year\": 2002,\n      \"claim\": \"Epistasis experiments in NK cells placed SYK upstream of PI3K in DAP12-mediated cytotoxicity and IL-2 survival signaling, defining the SYK→PI3K→Rac1→AKT axis as a core cascade in innate lymphocytes.\",\n      \"evidence\": \"Dominant-negative SYK, pharmacological inhibition, constitutively active PI3K/Rac1 rescue in NK cells\",\n      \"pmids\": [\"11907067\", \"12393431\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Direct phosphorylation of PI3K subunits by SYK was not demonstrated\", \"Contribution of other kinases to PI3K activation was not excluded\"]\n    },\n    {\n      \"year\": 2006,\n      \"claim\": \"Showing that SYK is required for complement receptor CR3-mediated phagocytosis and RhoA/Vav activation defined a second phagocytic receptor pathway dependent on SYK, paralleling the Fcγ receptor pathway.\",\n      \"evidence\": \"SYK siRNA and dominant-negative SYK in HL60 cells; CR3-dependent zymosan uptake and RhoA/Vav phosphorylation\",\n      \"pmids\": [\"16449524\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Whether SYK directly phosphorylates Vav or acts through intermediates was unresolved\"]\n    },\n    {\n      \"year\": 2008,\n      \"claim\": \"Demonstrating that Dectin-1/SYK cooperates with multiple TLRs for sustained NF-κB activation established SYK as an integrator of innate pattern-recognition signals beyond single-receptor pathways.\",\n      \"evidence\": \"Syk-deficient and MyD88-deficient macrophages; IκB degradation and NF-κB translocation assays\",\n      \"pmids\": [\"18200499\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Molecular mechanism of TLR–SYK convergence on NF-κB was not identified\", \"Whether CARD9 mediates all SYK-dependent NF-κB in this context was untested\"]\n    },\n    {\n      \"year\": 2010,\n      \"claim\": \"Resolving the phosphorylation hierarchy — Lyn exclusively phosphorylates Tyr-346 while other sites are dual Lyn/autophosphorylation targets — and identifying C-terminal tyrosines (Tyr-623/624/625) as regulators of kinase activity and ITAM binding provided a detailed activation map of SYK.\",\n      \"evidence\": \"Selective kinase inhibitors, kinase-dead SYK, Lyn siRNA in mast cells; C-terminal tyrosine mutagenesis with reconstitution in Syk-deficient mast cells\",\n      \"pmids\": [\"20828828\", \"20554527\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"The phosphatase(s) that dephosphorylate each specific site were not identified\", \"Structural consequence of C-terminal tyrosine phosphorylation was not determined\"]\n    },\n    {\n      \"year\": 2010,\n      \"claim\": \"Determining that CLEC-2 hemITAM dimers recruit SYK in a 2:1 stoichiometry established an alternative mode of SYK engagement distinct from the dual-ITAM model.\",\n      \"evidence\": \"SPR, peptide pulldown, tryptophan fluorescence, cross-linking, EM with CLEC-2 tail peptides\",\n      \"pmids\": [\"20154219\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Whether hemITAM-bound SYK achieves equivalent catalytic output to ppITAM-bound SYK was unknown\"]\n    },\n    {\n      \"year\": 2012,\n      \"claim\": \"The crystal structure of full-length autoinhibited SYK showed that ppITAM binding allosterically remodels the ATP-binding site, providing the first structural framework for the SYK activation mechanism.\",\n      \"evidence\": \"X-ray crystallography of full-length wild-type and Y348F/Y352F SYK with AMP-PNP; SPR, ITC, autophosphorylation assays\",\n      \"pmids\": [\"23154170\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Structure of fully activated (linker-phosphorylated) SYK was not obtained\", \"Dynamics of conformational change in membranes were not captured\"]\n    },\n    {\n      \"year\": 2019,\n      \"claim\": \"Demonstrating that ppITAM binding alone is insufficient to fully activate monomeric SYK and that sequential LYN-mediated Tyr-352→Tyr-348 phosphorylation is required resolved a longstanding question about the obligatory role of Src-family kinase priming.\",\n      \"evidence\": \"In vitro kinase assay with monomeric untagged recombinant SYK; phosphoproteomics\",\n      \"pmids\": [\"30923129\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Whether this two-step mechanism operates identically across all ITAM-bearing receptors was not tested\"]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"Identifying Cbl-mediated SYK degradation as a gatekeeper of germinal center B cell fate — attenuating BCR signal intensity to favor dark-zone recycling over plasma cell differentiation — connected SYK protein turnover to adaptive immune output.\",\n      \"evidence\": \"Mouse model defective in Cbl-mediated SYK degradation; Kras/ERK and PI3K/Foxo1 pathway analysis; GC B cell flow cytometry\",\n      \"pmids\": [\"31873727\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Specific ubiquitin linkage type on SYK by Cbl was not defined\", \"Whether USP10 counteracts Cbl in GC B cells was not tested\"]\n    },\n    {\n      \"year\": 2021,\n      \"claim\": \"Discovery that TRIM31 catalyzes K27-linked polyubiquitination of SYK at Lys-375/517 to promote its membrane translocation and shield it from SHP-1 revealed a positive regulatory ubiquitination pathway distinct from Cbl-mediated degradative ubiquitination.\",\n      \"evidence\": \"Reconstituted ubiquitination assay, K375/517 mutagenesis, Trim31−/− mice, Candida infection model\",\n      \"pmids\": [\"34362877\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Whether other E3 ligases also catalyze non-degradative SYK ubiquitination is unknown\", \"Structural basis for K27-linked ubiquitin recognition by downstream effectors was not determined\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Conditional SYK deletion in microglia ablated TREM2-dependent plaque encasement and the PI3K–AKT–mTOR axis required for the disease-associated microglia program, positioning SYK as an essential transducer in neurodegeneration-associated microglial activation.\",\n      \"evidence\": \"SYK conditional KO in microglia, TREM2R47H knock-in mice, anti-CLEC7A antibody rescue, Aβ plaque assays\",\n      \"pmids\": [\"36306735\", \"36257314\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Whether SYK inhibition is therapeutically beneficial or detrimental in Alzheimer's disease is unresolved\", \"SYK substrates specific to microglia were not catalogued\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"The structural basis for full SYK activation in the membrane context (linker-phosphorylated, ITAM-bound), the complete inventory of direct SYK substrates across cell types, and whether SYK's tumor-suppressor and neuroinflammatory roles can be therapeutically separated remain open questions.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"No structure of membrane-associated, fully activated SYK exists\", \"Comprehensive substrate identification across cell types is lacking\", \"Therapeutic window for SYK modulation in neurodegeneration versus immunity is undefined\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0140096\", \"supporting_discovery_ids\": [1, 2, 5, 6, 7]},\n      {\"term_id\": \"GO:0098772\", \"supporting_discovery_ids\": [23, 36]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005829\", \"supporting_discovery_ids\": [1, 16]},\n      {\"term_id\": \"GO:0005886\", \"supporting_discovery_ids\": [0, 3, 12, 25]},\n      {\"term_id\": \"GO:0005634\", \"supporting_discovery_ids\": [16]},\n      {\"term_id\": \"GO:0005815\", \"supporting_discovery_ids\": [17]},\n      {\"term_id\": \"GO:0005768\", \"supporting_discovery_ids\": [25]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-168256\", \"supporting_discovery_ids\": [1, 2, 8, 9, 18, 22, 27, 29, 42]},\n      {\"term_id\": \"R-HSA-162582\", \"supporting_discovery_ids\": [5, 18, 19, 28, 29, 40]},\n      {\"term_id\": \"R-HSA-109582\", \"supporting_discovery_ids\": [0, 3, 30]},\n      {\"term_id\": \"R-HSA-5357801\", \"supporting_discovery_ids\": [23, 41]},\n      {\"term_id\": \"R-HSA-1266738\", \"supporting_discovery_ids\": [27, 30]},\n      {\"term_id\": \"R-HSA-9612973\", \"supporting_discovery_ids\": [26, 34]}\n    ],\n    \"complexes\": [],\n    \"partners\": [\n      \"LYN\",\n      \"BLNK\",\n      \"BTK\",\n      \"CLEC1B\",\n      \"CBL\",\n      \"TRIM31\",\n      \"USP10\",\n      \"TREM2\"\n    ],\n    \"other_free_text\": []\n  }\n}\n```"}