Figure 2.

JAK/STAT signaling pathway. Cytokine binds with the target receptor; this causes dimerization of receptor chains and the juxtaposition of JAKs, and their reciprocal phosphorylation. Once activated, JAKs phosphorylate the intra-cytoplasmic regions of the cytokine receptor; creating a docking site for cytoplasmatic STATs that once joined with the receptor are activated by JAK phosphorylation in a tyrosine residue. STATs dimers act as transcriptional factors recognizing specific DNA sequences.