JAK 3 ( janus kinase 3 or just another kinase 3 )

JAK3 is expressed in 12 normal human tissues (bone marrow, spleen, thymus, brain, spinal cord, heart, skeletal muscle, liver, pancreas, prostate, kidney, and lung). JAK3S is more commonly seen in hematopoietic cells, whereas JAK3B and JAK3M are detected in cells of hematopoietic or epithelial origin. Localisation Intracellular, membrane-associated through association with interleukin (IL) receptor common gamma chain (gamma-c). Function Tyrosine kinase of the non-receptor type. Involved in the signaling of ILs that contain the gamma-c chain in their respective receptors, including IL-2, IL-4, IL-7, IL-9, IL-15, and IL-21. Induces tyrosine phosphorylation of a number of proteins, of which most widely studied are signal transducers and activators of transcriptions (STAT). JAK3 has also been shown to phosphorylate insulin receptor substrate-1 (IRS-1), IRS-2, and PI3K/Akt. Homology JAK3 is the most recently identified member of the mammalian Janus kinase subfamily (TYK2, JAK1, JAK2, and JAK3); JAK3 paralogs to JAK1 and JAK2; human JAK3 orthologs to murine Jak3.