Syk a cytoplasmic tyrosine kinase of the SYK family containing two SH2 domains. Mediates signal transduction downstream of the B-cell antigen receptor (BCR) as well as a variety of other transmembrane receptors. Regulates several biological processes including innate and adaptive immunity, cell adhesion, osteoclast maturation, platelet activation and vascular development. Assembles into signaling complexes with activated receptors at the plasma membrane via interaction between its SH2 domains and the receptor tyrosine-phosphorylated ITAM and partial hemITAM domains. Direct downstream effectors phosphorylated by SYK include VAV1, PLCG, PI-3-kinase, LCP2 and BLNK. 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. Plays a role in T-cell receptor signaling and in the innate immune response to fungal, bacterial and viral pathogens. 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. Required for the stimulation of neutrophil phagocytosis by IL15. Involved in the activation of dendritic cells by cell necrosis stimuli, and in mast cells activation. Involved in interleukin-3/IL3-mediated signaling pathway in basophils. Functions downstream of receptors mediating cell adhesion. Is involved in vascular development where it may regulate blood and lymphatic vascular separation. Required for osteoclast development and function. Functions in the activation of platelets by collagen, mediating PLCG2 phosphorylation and activation. 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. Expression highest in murine spleen, heart, mammary gland and thymus. Widely expressed in hematopoietic cells. Expressed in neutrophils. Within the B-cell compartment, expressed from pro- and pre-B cells to plasma cells. 2 alternatively spliced human isoforms have been reported. Note: This description may include information from UniProtKB.
Protein type: EC; Kinase, protein; Protein kinase, TK; Protein kinase, tyrosine (non-receptor); Syk family; TK group
Chromosomal Location of Human Ortholog: 17p14
Cellular Component:  B cell receptor complex; cytoplasm; cytosol; early phagosome; nucleus; plasma membrane; protein-containing complex; T cell receptor complex
Molecular Function:  ATP binding; integrin binding; interleukin-15 receptor binding; non-membrane spanning protein tyrosine kinase activity; phosphatase binding; phosphotyrosine residue binding; protein binding; protein domain specific binding; protein kinase activity; protein kinase binding; protein serine/threonine kinase activity; protein tyrosine kinase activity; SH2 domain binding; Toll-like receptor binding; ubiquitin protein ligase binding
Biological Process:  activation of JUN kinase activity; activation of MAPK activity; adaptive immune response; angiogenesis; B cell receptor signaling pathway; beta selection; blood vessel morphogenesis; cell surface receptor signaling pathway; cellular response to low-density lipoprotein particle stimulus; cellular response to molecule of fungal origin; collagen-activated tyrosine kinase receptor signaling pathway; defense response to bacterium; enzyme linked receptor protein signaling pathway; innate immune response; integrin-mediated signaling pathway; interleukin-3-mediated signaling pathway; intracellular signal transduction; leukocyte activation involved in immune response; leukocyte cell-cell adhesion; leukotriene biosynthetic process; lymph vessel development; macrophage activation involved in immune response; neutrophil activation involved in immune response; neutrophil chemotaxis; peptidyl-serine phosphorylation; peptidyl-tyrosine phosphorylation; positive regulation of alpha-beta T cell differentiation; positive regulation of alpha-beta T cell proliferation; positive regulation of B cell differentiation; positive regulation of bone resorption; positive regulation of calcium-mediated signaling; positive regulation of cell adhesion mediated by integrin; positive regulation of cold-induced thermogenesis; positive regulation of cytokine secretion; positive regulation of gamma-delta T cell differentiation; positive regulation of granulocyte macrophage colony-stimulating factor biosynthetic process; positive regulation of interleukin-3 biosynthetic process; positive regulation of interleukin-4 production; positive regulation of mast cell degranulation; positive regulation of peptidyl-tyrosine autophosphorylation; positive regulation of peptidyl-tyrosine phosphorylation; positive regulation of receptor internalization; positive regulation of type I interferon production; protein autophosphorylation; protein import into nucleus; protein phosphorylation; receptor internalization; regulation of arachidonic acid secretion; regulation of DNA-binding transcription factor activity; regulation of ERK1 and ERK2 cascade; regulation of immune response; regulation of neutrophil degranulation; regulation of phagocytosis; regulation of platelet activation; regulation of platelet aggregation; regulation of superoxide anion generation; regulation of tumor necrosis factor-mediated signaling pathway; serotonin secretion; serotonin secretion by platelet
Reference #:  Q64725 (UniProtKB)
Alt. Names/Synonyms: KSYK; p72syk; Spleen tyrosine kinase; Syk; Tyrosine-protein kinase SYK
Gene Symbols: Syk
Molecular weight: 71,529 Da
Basal Isoelectric point: 8.32  Predict pI for various phosphorylation states
CST Pathways:  B Cell Receptor Signaling  |  ErbB/HER Signaling  |  PI3K/Akt Signaling  |  Tyrosine Kinases & Substrates
Protein-Specific Antibodies, siRNAs or Recombinant Proteins from Cell Signaling Technology® Total Proteins
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Cross-references to other databases:  STRING  |  Reactome  |  BioGPS  |  Pfam  |  ENZYME  |  Phospho.ELM  |  NetworKIN  |  UniProtKB  |  Entrez-Gene  |  Ensembl Gene