JAK/STAT Signaling PathwayChemicals ResearchUpdated on Dec 11, 2018 View more like this | Visit SHIRLEY, NY | Contact BOCSCI INC |

Introduction
The janus kinase/signal transducers and activators of transcription (JAK/STAT) signaling pathway was discovered by Darnell in 1994 and is an important pathway for cytokine signaling. It is activated by a variety of cytokines, growth factors and receptors, and is involved in cell proliferation, differentiation, apoptosis, angiogenesis and immune regulation, and plays an important role in the occurrence and development of tumors. Abnormal activation of this pathway leads to clonal proliferation and tumor formation.
Figure 1. Model of JAK/STAT Signaling in the Regulation of Whole-Body Metabolism
JAK/STAT Family Member
JAK is a class of non-receptor tyrosine kinases, including JAK1, JAK2, JAK3 and TYK2. There are 7 domains of JH1-7 in the molecular structure. JH1 has catalytic function and JH2 participates in the catalytic function of JH1. However, the function of JH3-JH7 is currently underreported, suggesting that it may play a role in the coupling of receptors to JAKs. Shan et al. found that the JAKs family has a conserved tyrosine kinase domain at the C-terminus and is highly conserved in evolution. JAK1, JAK2, and TYK2 expression were detected in most tissue cells, and JAK3 was expressed only in bone marrow and lymphocytes.
STATs mainly include STAT1, 2, 3, 4, 5, and 6, wherein STAT5 is further divided into two subtypes, STAT5a and STAT5b. STAT has been found to have six functional domains: DNA binding domain, amino terminal domain, coiled-coil domain, ligation domain, SH2/tyrosine phosphorylation domain, and transcriptional activation domain at the carboxy terminus. The DNA binding domain and the SH2 domain are highly similar, and this similarity contributes to the formation of dimers and the activation of STATs.
The janus kinase/signal transducers and activators of transcription (JAK/STAT) signaling pathway was discovered by Darnell in 1994 and is an important pathway for cytokine signaling. It is activated by a variety of cytokines, growth factors and receptors, and is involved in cell proliferation, differentiation, apoptosis, angiogenesis and immune regulation, and plays an important role in the occurrence and development of tumors. Abnormal activation of this pathway leads to clonal proliferation and tumor formation.
Figure 1. Model of JAK/STAT Signaling in the Regulation of Whole-Body Metabolism
JAK/STAT Family Member
JAK is a class of non-receptor tyrosine kinases, including JAK1, JAK2, JAK3 and TYK2. There are 7 domains of JH1-7 in the molecular structure. JH1 has catalytic function and JH2 participates in the catalytic function of JH1. However, the function of JH3-JH7 is currently underreported, suggesting that it may play a role in the coupling of receptors to JAKs. Shan et al. found that the JAKs family has a conserved tyrosine kinase domain at the C-terminus and is highly conserved in evolution. JAK1, JAK2, and TYK2 expression were detected in most tissue cells, and JAK3 was expressed only in bone marrow and lymphocytes.
STATs mainly include STAT1, 2, 3, 4, 5, and 6, wherein STAT5 is further divided into two subtypes, STAT5a and STAT5b. STAT has been found to have six functional domains: DNA binding domain, amino terminal domain, coiled-coil domain, ligation domain, SH2/tyrosine phosphorylation domain, and transcriptional activation domain at the carboxy terminus. The DNA binding domain and the SH2 domain are highly similar, and this similarity contributes to the formation of dimers and the activation of STATs.