Janus kinase 1 and Janus kinase 2 (JAK1, JAK2)

Janus kinase 1 (JAK1) and Janus kinase 2 (JAK2) are cytoplasmic, non-receptor tyrosine kinases that mediate intracellular signaling from type I and type II cytokine receptors via the JAK-STAT pathway. Upon cytokine binding to their respective receptors, JAK1 and JAK2 are activated, leading to phosphorylation of STAT transcription factors which translocate to the nucleus to modulate gene expression. These kinases play essential roles in immune function, hematopoiesis, and inflammation; genetic mutations (notably JAK2 V617F) or dysregulation are implicated in myeloproliferative neoplasms, various cancers, and autoimmune or inflammatory diseases. Therapeutically, JAK1 and JAK2 are major drug targets for a range of approved and investigational small-molecule inhibitors, collectively known as JAK inhibitors.

Other names

JAK1: Tyrosine-protein kinase JAK1JAK2: Tyrosine-protein kinase JAK2Common: JAK kinasesCommon: Janus kinases

Inhibition of JAK1 and/or JAK2 kinase activity; Blockade of JAK-STAT pathway signal transduction; Suppression of downstream cytokine signaling