A Transcription Factor-Centric View of Transcription Regulation

Transcription is arguably the most critical regulatory step in gene expression. In eukaryotes, a promoter is necessary for transcription, but it alone often does not lead to significant gene transcription. Distal regulatory elements called enhancers can greatly increase transcription levels. Sequence-specific transcription factors recruited to the enhancers play pivot roles in regulating promoter activities. These enhancer-bound transcription factors represent a central node in biological regulation, by converting various internal and external regulatory signals into biological responses in the form of target gene transcription. In this review, we take a transcription factor-centric view, and summarize recent advances in our understanding of how transcription factors regulate promoter activities. We also highlight significant outstanding questions in the field, and propose possible strategies to solve these questions.