What is a transcriptional activator?

A transcriptional activator is a protein that increases gene transcription. These proteins play a crucial role in the regulation of gene expression by binding to specific DNA sequences known as enhancers or promoters. When a transcriptional activator binds to these regions, it facilitates the assembly of the transcription machinery and enhances the recruitment of RNA polymerase to the promoter, leading to an increased rate of transcription of the corresponding gene.

Transcriptional activators can function through various mechanisms, including altering the accessibility of DNA by modifying chromatin structure, interacting with other proteins, or recruiting co-activators that assist in forming the transcriptional complex. This process is essential for regulating diverse cellular functions, allowing cells to respond to environmental signals, differentiate, and maintain homeostasis.