Description
STAT proteins (Signal transducer and activator of transcription) belong to a family of cytoplasmic transcription factors that can be phosphorylated by a lignad binding to its cell surface receptor. The phosphorylation of STAT3 induces STAT dimerization, nuclear translocation and DNA binding. Stat3 is constitutively activated in a number of human tumors. Stat3- activated transcription seems to be regulated by serine phosphorylation at Ser727 and tyrosine phosphorylation at Tyr705