Figure 3.

JAK-STAT signaling. Upon ligand-mediated receptor dimerization, JAKs are phosphorylated and activated, which in turn induces tyrosine phosphorylation of the cytosolic receptor tails. Receptor phosphorylation forms docking sites for receptor-specific STAT proteins, which are subsequently activated by phosphorylation. Activated STAT proteins form homo- or heterodimers that pass through the nuclear membrane through nuclear pore complexes (NPCs) [40] and successively bind to specific enhancer sequences in target genes, impacting their transcription [41].