Promoter

Promoter

A promoter is a region of DNA that initiates transcription of a particular gene. It is located upstream of the coding sequence and contains binding sites for RNA polymerase and transcription factors. Promoters themselves do not encode proteins but help determine when and where a gene is transcribed, contributing to the temporal and spatial patterns of gene expression.

In prokaryotes, promoters are recognized mainly by the RNA polymerase holoenzyme that includes a sigma factor. Core promoter elements commonly occur near the transcription start site, notably at approximately -10 and -35 bases from this site. The near-consensus sequences are often referred to as the Pribnow box (-10) and the -35 region. Regulatory proteins can modulate promoter activity by binding nearby sequences or interacting with the polymerase, allowing responses to environmental conditions.

In eukaryotes, promoters are more diverse. The core promoter may feature motifs such as a TATA box, initiator element, or other elements, and is often supplemented by proximal promoter regions rich in transcription factor binding sites. Promoters recruit RNA polymerase II and assemble the transcription machinery; their activity is influenced by enhancers, chromatin state, epigenetic marks, and three-dimensional genome organization. Promoter strength and specificity can vary across tissues and developmental stages.

Promoter can also refer to a person or organization that promotes events, such as concerts or sports, handling booking, marketing, logistics, and venue coordination. In both senses, promoters play a key role in initiating and regulating activity, whether at the level of gene expression or public entertainment.

Etymology: promoter derives from Latin promovere, meaning to move forward.