Regulated transcription is driven by signals from outside the cell.

These signals are transferred through a series of proteins by way of phosphorylation.

The final protein in this series must then enter the nucleus. Transcription only occurs in the nucleus of the cell.

After entering the nucleus, the protein interacts with a specific transcription factor.

After receiving the signal that originally came from outside the cell, the transcription factor binds to a section of DNA known as an enhancer region.

The transcription factor then moves to interact with the rest of the transcription complex and transcription can begin.