In molecular genetics, a repressor is a DNA-or RNA-binding protein that inhibits the expression of one or more genes by binding to the operator or associated silencers. A DNA-binding repressor blocks the attachment of RNA polymerase to the promoter, thus preventing transcription of the genes into messenger RNA.

2 天之前 · Repressors are proteins that turn off or reduce gene expression, which is reflected by reduced messenger RNA production from the affected gene. Repressor proteins typically function through binding and blocking critical DNA sequences in the gene, such as the promoter where mRNA transcription starts.

2024年11月23日 · Transcriptional repressors can bind to promoter or enhancer regions and block transcription. Like the transcriptional activators, repressors respond to external stimuli to prevent the binding of activating transcription factors.

The model proposed the existence of a new class of genes, termed regulator genes, which were responsible for the synthesis of a substance, later determined to be a protein of about 160 000 molecular weight, which was termed a repressor.

When a gene is regulated by a repressor, the process is called negative regulation. Both strong and weak promoters can be regulated by repressors. A single gene can be regulated by both activators and repressors.

The Drosophila repressor Brinker protein displays gene specific effects, relying on either CtBP or Groucho complex to repress different target genes . Even distinct enhancers from the same gene can show cofactor specific effects.

2021年12月16日 · Transcriptional repressors can bind to promoter or enhancer regions and block transcription. Like the transcriptional activators, repressors respond to external stimuli to prevent the binding of activating transcription factors.

Silencers are regulatory DNA elements that reduce transcription from their target promoters; they are the repressive counterparts of enhancers. Although discovered decades ago, and despite evidence of their importance in development and disease, silencers have been much less studied than enhancers.

2013年2月1日 · Here, we review the evidence for the presence of repressors at actively transcribed regions and assess what roles they might be playing. We propose that the modulation of expression levels by chromatin-modifying, co-repressor complexes provides transcriptional fine-tuning that drives development.

2025年2月3日 · This is a summary of: McLean, T. C. et al. KorB switching from DNA-sliding clamp to repressor mediates long-range gene silencing in a multi-drug resistance plasmid. Nat. Microbiol .