The Hierarchy of Transcriptional Activation: From Enhancer to Promoter

Regulatory elements (enhancers) that are remote from promoters play a critical role in the spatial, temporal, and physiological control of gene expression. Studies on specific loci, together with genome-wide approaches, suggest that there may be many common mechanisms involved in enhancer–promoter communication. Here, we discuss the multiprotein complexes that are recruited to enhancers and the hierarchy of events taking place between regulatory elements and promoters.

TrendsEnhancers are first primed by pioneer transcription factors (TFs).Other TFs are likely required for subsequent events.There is a hierarchy between enhancers and the promoters that they regulate.Enhancers and promoters share similar properties, but differ in the characteristics and the abundance of the RNAs that they produce.By recruiting the preinitiation complex and other proteins, enhancers have a role of increasing the concentration of the transcription machinery at target promoters.