JAK3 Kinase Domain (human, recombinant)

JAK3 is a non-receptor tyrosine kinase that has roles in cytokine signaling and immune cell function.1,2 It is composed of N-terminal FERM and SH2 domains, a regulatory JH2 pseudokinase domain, and a C-terminal kinase domain.2,3 JAK3 is constitutively expressed in natural killer (NK) cells and thymocytes and expressed upon cell activation in T cells, B cells, and monocytes.4 Following cytokine binding to the IL-2 receptor (IL-2R), IL-4R, IL-7R, IL-9R, IL-15R, or IL-21R, JAK3 binds to the gammac subunit of the receptor and induces heterodimerization of the receptor subunits and activation of STAT transcription factors.1,2,4 Through activation of these receptors, JAK3-mediated signaling is involved in T cell proliferation, differentiation, and survival, B cell differentiation and function, and macrophage activation, among other activities.1,2 Loss-of-function mutations in JAK3 are associated with autosomal recessive severe combined immunodeficiency disease (SCID), while gain-of-function mutations are associated with immune dysregulation and blood cancers, including myeloproliferative neoplasms, T cell lymphomas and leukemias, NK lymphoma-leukemia, and acute lymphoblastic leukemia.2,5,6 Cayman's JAK3 Kinase Domain (human, recombinant) protein can be used for enzyme activity assays. This protein has a calculated molecular weight of 37 kDa. WARNING This product is not for human or veterinary use. Purity: >90% estimated by SDS-PAGE. Source: Active recombinant human N-terminal His-tagged JAK3 kinase domain expressed in insect cells (Sf9). Amino Acids: 811-1,124. MW: 37 kDa. Formulation: 40 mM Tris-HCl, pH 8.0, with 110 mM sodium chloride, 2.2 mM potassium chloride, 3 mM DTT, 20% glycerol, and 200 mM imidazole.