Janus kinase 1 & Janus kinase 3 (JAK1 & JAK3)

Janus kinase 1 (JAK1) and Janus kinase 3 (JAK3) are members of the Janus kinase family, which act as cytoplasmic, non-receptor tyrosine kinases essential for cytokine receptor signaling, especially in hematopoietic and immune cells. JAK1 is broadly expressed, transmitting signals from multiple cytokine receptors (including type I and type II cytokine receptors), and is central to innate and adaptive immune signaling and inflammation. JAK3 expression is largely limited to hematopoietic and lymphoid cells, where it associates with the common gamma chain of multiple cytokine receptors, and is essential for lymphocyte development and immune function[5][7][10]. Inhibitors targeting JAK1 and JAK3 are established therapies for autoimmune diseases and are under study for cancer and other inflammatory conditions, however, their use is associated with specific safety concerns, including immunosuppression and risk of thromboembolism[2][3][6].

Other names

Janus kinase IJanus kinase-1Janus kinase IIIJanus kinase-3

Competitive inhibition of the ATP-binding site in the kinase domain, blocking downstream phosphorylation events; Suppression/inhibition of cytokine signal transduction mediated by JAK-STAT pathway; Modulation of T cell and B cell development and function