Distinguish between the cis-acting regulatory elements referred to as promoters and enhancers.

Key Concepts

Promoters

Promoters are specific DNA sequences located upstream of a gene that serve as binding sites for RNA polymerase and transcription factors. They are essential for initiating the transcription of the gene into mRNA. Promoters typically contain conserved sequences, such as the TATA box, which help in the recruitment of the transcription machinery.

Enhancers

Enhancers are regulatory DNA sequences that can significantly increase the transcription of a gene, even though they may be located far away from the promoter. They function by binding transcription factors and facilitating the looping of DNA to bring these factors into proximity with the promoter, thereby enhancing gene expression. Enhancers can work in a tissue-specific manner, influencing when and where genes are expressed.

Cis-acting Elements

Cis-acting elements are regions of non-coding DNA that regulate the transcription of nearby genes. Both promoters and enhancers are considered cis-acting elements because they exert their effects on the same DNA molecule. Understanding the distinction between these elements is crucial for grasping how gene expression is finely tuned in response to various cellular signals.