The protein encoded by this gene is a member of the STAT
protein family. In response to cytokines and growth factors, STAT
family members are phosphorylated by the receptor associated
kinases, and then form homo- or heterodimers that translocate to
the cell nucleus where they act as transcription activators. This
protein is activated through phosphorylation in response to various
cytokines and growth factors including IFNs, EGF, IL5, IL6, HGF,
LIF and BMP2. This protein mediates the expression of a variety of
genes in response to cell stimuli, and thus plays a key role in
many cellular processes such as cell growth and apoptosis. The
small GTPase Rac1 has been shown to bind and regulate the activity
of this protein. PIAS3 protein is a specific inhibitor of this
protein. Three alternatively spliced transcript variants encoding
distinct isoforms have been described.
