a non-receptor tyrosine-kinase of the Jak family expressed predominantly in immune cells. Mediates signal transduction via the common gamma-chain of cytokine receptors, including IL-2, -4, -7, -9, and -15. Interacts with members of the STAT (signal transduction and activators of transcription) family. Interacts with STAM2 and SHB. Contains two protein kinase domains. Mutations that abrogate JAK3 function cause an autosomal SCID (severe combined immunodeficiency disease). Inhibitor: R017s for organ transplants. Three differentially spliced isoforms have been described. Note: This description may include information from UniProtKB.
Protein type: Protein kinase, tyrosine (non-receptor); Kinase, protein; EC 188.8.131.52; Protein kinase, TK; TK group; JakA family
Molecular Function: protein binding; protein-tyrosine kinase activity; non-membrane spanning protein tyrosine kinase activity; ATP binding
Biological Process: positive regulation of immune response; negative regulation of interleukin-12 production; peptidyl-tyrosine phosphorylation; negative regulation of T-helper 1 cell differentiation; negative regulation of interleukin-10 production; negative regulation of FasL biosynthetic process; protein amino acid autophosphorylation; protein kinase cascade; positive regulation of activated T cell proliferation; protein amino acid phosphorylation; enzyme linked receptor protein signaling pathway; tyrosine phosphorylation of Stat5 protein; regulation of apoptosis; tyrosine phosphorylation of STAT protein; negative regulation of dendritic cell cytokine production; elevation of cytosolic calcium ion concentration; B cell differentiation; innate immune response; positive regulation of transcription from RNA polymerase II promoter; T cell homeostasis; positive regulation of calcium ion transport; negative regulation of T cell activation; negative regulation of apoptosis; STAT protein nuclear translocation
SS: The number of records in which this modification site was determined using site-specific methods. SS methods include amino acid sequencing, site-directed mutagenesis, modification site-specific antibodies, specific MS strategies, etc.