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: Kinase, protein; EC 126.96.36.199; Protein kinase, TK; Protein kinase, tyrosine (non-receptor); TK group; JakA family
Molecular Function: protein binding; protein-tyrosine kinase activity; non-membrane spanning protein tyrosine kinase activity; protein phosphatase binding; ATP binding
Biological Process: negative regulation of interleukin-12 production; peptidyl-tyrosine phosphorylation; negative regulation of T-helper 1 cell differentiation; negative regulation of FasL biosynthetic process; negative regulation of interleukin-10 production; protein kinase cascade; enzyme linked receptor protein signaling pathway; protein amino acid phosphorylation; negative regulation of dendritic cell cytokine production; tyrosine phosphorylation of STAT protein; B cell differentiation; innate immune response; T cell homeostasis; positive regulation of transcription from RNA polymerase II promoter; negative regulation of T cell activation; 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.