Phospho-Jak3 (Tyr980/981) (Clone: E10) rabbit mAb

Members of the Janus family of tyrosine kinases (Jak1, Jak2, Jak3, and Tyk2) transmit information from extracellular chemical signals to the nucleus resulting DNA transcripotion (1) . Binding of ligands including cytokines to their specific transmembrane receptors activate associated JAKs. Subsequently activated JAKs (Janus kinases) phosphorylate tyrosine residues on the receptor, creating docking sites for latent STAT proteins (Signal Transducer and Activator of Transcription) . After recruitment of STAT to the receptor, they are also phosphorylated by JAKs. Activated STATs migrate to the nucleus of the cell and promote gene transcription or induction. (2-4) . In mammals the JAK/STAT family consists of four JAK members, JAK1, JAK2, JAK3 and TYK2 and seven STAT members, STAT1, STAT2, STAT3, STAT4, STAT5a, TAT5b, STAT6. The JAKs are activated by different receptos and have, therfore, distinct in vivo roles. Jak3 is maninly expressed B and T lymphocytes and is required for lymphocyte and function and deveopment. Jak3 is phosphorylated in multiple site including Tyr980, Tyr 981.