Figure 1.

Schematic representation of JAK-STAT structure. (A) The domain structure of JAKs and STATs. Four JAKs consist of the domains JH1 to JH7 based on their sequence similarity including 2 tyrosines after cytokine stimulation. JH1 is kinase domain and JH2 is the pseudo-kinase domain. The JH6 and JH7 domains introduce the binding of JAKs to main receptors. STATs consist of 7 specific domains, which are involved with various responses resulting in the regulation of protein modification by tyrosine and serine phosphorylation, methylation, sumoylation, and acetylation. (B) Classification of cytokine receptors which are type I and II according to their ligands and the association with JAKs to deliver their signals to the downstream.

FERM, 4.1, ezrin, radixin, moesin; TAD, transactivation domain; GM-CSFR, granulocyte-macrophage colony-stimulating factor receptor; EPOR, erythropoietin receptor; TPOR, thrombopoietin receptor; G-CSF, granulocyte-colony stimulating factor; IFN, interferon.