Janus kinase

Janus kinase (JAK) is a family of intracellular, non-receptor tyrosine kinases that transduce cytokine-mediated signals via the JAK-STAT pathway. They were initially named "just another kinase" 1 and 2 (since they were just two of many discoveries in a PCR-based screen of kinases),[1] but were ultimately published as "Janus kinase". The name is taken from the two-faced Roman god of beginnings, endings and duality, Janus, because the JAKs possess two near-identical phosphate-transferring domains. One domain exhibits the kinase activity, while the other negatively regulates the kinase activity of the first.

  1. ^ Wilks (1989). "Two putative protein-tyrosine kinases identified by application of the polymerase chain reaction". PNAS. 86 (5): 1603–7. Bibcode:1989PNAS...86.1603W. doi:10.1073/pnas.86.5.1603. PMC 286746. PMID 2466296.