Mechanisms of action of transcription activation and repression domains

Transcriptional regulators contain domains that either activate or repress transcription. Indeed, many cellular transcriptional regulators contain bot h activation and repression domains. Transcriptional regulators act at seve ral stages in the transcription process, including assembly of the transcri ption complex, initiation and elongation. In order to influence these proce sses, the regulatory domains must interact with components of the transcrip tion apparatus. This review will focus on our current understanding of the nature of transcriptional regulatory domains and their targets in the trans cription machinery.