JAK2 [MD349R]

JAK2 is a member of the Janus family of tyrosine kinases (JAK1, JAK2, JAK3, and TYK2), which are activated by ligands binding to a number of associated cytokine receptors and become autophosphorylated and phosphorylate their associated receptors to provide multiple binding sites for signaling proteins. These associated signaling proteins, such as Stats, Shc, insulin receptor substrates, and focal adhesion kinase (FAK), typically contain SH2 or other phospho-tyrosine-binding domains. JAK2 is required for the IFN gamma-receptor complex initiation and JAK1 functions as an amplifier. Some studies have suggested that the role of JAK2 might be performed by Tyk2 and JAK3, if they were positioned correctly within the IFN gamma-receptor complex. Mutations affecting JAK2 can cause Budd-Chiari syndrome, Polycythemia vera, Thrombocythemia 3, myelofibrosis, or acute myelogenous leukemia.