a tyrosine kinase of the Syk family. Plays an essential role in regulation of the adaptive immune response. Phosphorylates two essential T cell adapter proteins: the linker for activation of T-cells (LAT) protein and LCP2. Regulates lymphocyte activation, motility, adhesion and cytokine expression of mature T-cells. Promotes survival and cell-cycle progression of developing double-negative thymocytes before positive selection. Associates with the T-cell antigen receptor (TCR) zeta-chain and is phosphorylated by Lck following antigen receptor activation. Required for internalization and degradation of the TCR complex through interaction with the E3 ubiquitin-protein ligase CBL and adapter proteins SLA and SLA2. Three alternatively spliced isoforms of the human protein have been described. Note: This description may include information from UniProtKB.
Protein type: EC 126.96.36.199; Kinase, protein; Protein kinase, TK; Protein kinase, tyrosine (non-receptor); Syk family; TK group
Cellular Component: cytoplasm; cytosol; extrinsic to internal side of plasma membrane; lipid raft; plasma membrane; T cell receptor complex
Molecular Function: non-membrane spanning protein tyrosine kinase activity; protein binding; protein-tyrosine kinase activity; receptor binding
Biological Process: adaptive immune response; B cell activation; B cell receptor signaling pathway; immune response; inflammatory response; innate immune response; macrophage activation during immune response; neutrophil activation during immune response; peptidyl-tyrosine phosphorylation; positive regulation of alpha-beta T cell proliferation; positive regulation of B cell differentiation; positive regulation of cell adhesion mediated by integrin; positive regulation of mast cell degranulation; positive regulation of T cell differentiation; positive thymic T cell selection; protein amino acid phosphorylation; T cell activation; T cell receptor signaling pathway; transmembrane receptor protein tyrosine kinase signaling pathway