Anti-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. Protein function: Non-receptor tyrosine kinase involved in various processes such as cell growth, development, or differentiation. Mediates essential signaling events in both innate and adaptive immunity and plays a crucial role in hematopoiesis during T-cells development. In the cytoplasm, plays a pivotal role in signal transduction via its association with type I receptors sharing the common subunit gamma such as IL2R, IL4R, IL7R, IL9R, IL15R and IL21R. Following ligand binding to cell surface receptors, phosphorylates specific tyrosine residues on the cytoplasmic tails of the receptor, creating docking sites for STATs proteins. Subsequently, phosphorylates the STATs proteins once they are recruited to the receptor. Phosphorylated STATs then form homodimer or heterodimers and translocate to the nucleus to activate gene transcription. For example, upon IL2R activation by IL2, JAK1 and JAK3 molecules bind to IL2R beta (IL2RB) and gamma chain (IL2RG) subunits inducing the tyrosine phosphorylation of both receptor subunits on their cytoplasmic domain. Then, STAT5A AND STAT5B are recruited, phosphorylated and activated by JAK1 and JAK3. Once activated, dimerized STAT5 translocates to the nucleus and promotes the transcription of specific target genes in a cytokine-specific fashion. [The UniProt Consortium]