The cytokines: The interferon family - Pharmaceutical Biotechnology: Concepts and Aapplications - page 219

Ligand (e.g. a cytokine)

Plasma
membrane

Receptor ( + α chains)

β

Receptor dimerization
and phosphorylation

JAK

STAT

Association and
phosphorylation
of the STATs

Disassociation (and
dimerization) of
activated STATs, and
translocation to nucleus

Nucleus

Figure 8.2 Simplifi ed overview of the signal transduction process mediated by the JAK-STAT pathway. Refer
to text for specifi c details

NH 3 + COO -

C D SH3 SH2 Y Tr

Figure 8.3 Schematic representation of the general domain structure of a STAT protein. A conserved ('C' or
'con') domain is located at the N-terminus, followed by the DNA-binding domain (D). Y represents a short se-
quence that contains the tyrosine residue phosphorylated by the Janus kinase. The carboxy terminus domain
(T r ) represents a transcriptional activation domain