Roles of unphosphorylated STATs in signaling

Cell Res. 2008 Apr;18(4):443-51. doi: 10.1038/cr.2008.41.


The seven members of the signal transducer and activator of transcription (STAT) family of transcription factors are activated in response to many different cytokines and growth factors by phosphorylation of specific tyrosine residues. The STAT1 and STAT3 genes are specific targets of activated STATs 1 and 3, respectively, resulting in large increases in the levels of these unphosphorylated STATs (U-STATs) in response to the interferons (STAT1) or ligands that active gp130, such as IL-6 (STAT3). U-STATs drive gene expression by novel mechanisms distinct from those used by phosphorylated STAT (P-STAT) dimers. In this review, we discuss the roles of U-STATs in transcription and regulation of gene expression.

Publication types

  • Review

MeSH terms

  • Animals
  • DNA / metabolism
  • Gene Expression Regulation
  • Humans
  • Phosphorylation
  • Protein Transport
  • STAT Transcription Factors / metabolism*
  • Signal Transduction*


  • STAT Transcription Factors
  • DNA