Structure and Function of the Interferon-  Enhanceosome

A central problem in eukaryotic gene regulation is understanding how the transcription machinery is targetedto specific sets of genes in response to extracellular signals. A number of studies have shown that multicomponent transcription enhancer complexes are key regulatorycomponents in this process (for recent review, see Carey1998). These complexes, consisting of both transcriptional activator proteins and architectural proteins(Grosschedl 1995; Werner and Burley 1997), are assembled on specific DNA sequences when the appropriatesets of transcriptional activator proteins are coordinatelyactivated in response to a signal. The assembly of theseenhancer complexes is highly cooperative and promoteshigh levels of transcriptional synergy (Carey 1998). Thistranscriptional synergy is the consequence of multiple interactions within the enhancer complex, and between thiscomplex, general transcription factors and the multicomponent RNA polymerase II complex (Ptashne and Gann1997; Carey 1998)...