Gene Activation by the Cytokine-Driven Transcription Factor STAT1

Signal transducers and activators of transcription (STATs) are a family of cytokine-regulated transcription factors, which serve the dual role of external signal transduction and transcriptional activation. The founding member of this family, STAT1, is involved in a plethora of cellular processes, including interferon-dependent upregulation of various effector mechanisms in immune and non-immune cells to control bacterial, fungal and parasitic infections. In this chapter, we discuss the principles of STAT1-driven gene expression and focus on the clinical phenotypes of various human STAT1 mutations. In particular, we highlight the significance of sequence-specific DNA binding and intact nucleocytoplasmic shuttling for full transcriptional activation of interferon-driven target genes.