Table of Contents
Can a transcription factor both activate and repress transcription?
A certain transcription factor that binds a certain target sequence can act as activator and/or as repressor when it binds to different positions.
How are transcription factors inhibited?
Dimeric transcription factors need to form homodimers or heterodimers in order to activate transcription and to bind DNA. Thus, they can be inhibited by small-molecule inhibitors of the protein–protein interactions mediating the subunit association.
Is an activator a transcription factor?
A transcriptional activator is a protein (transcription factor) that increases transcription of a gene or set of genes. Activators are considered to have positive control over gene expression, as they function to promote gene transcription and, in some cases, are required for the transcription of genes to occur.
Can transcription factors repress transcription?
Some transcription factors bind to a DNA promoter sequence near the transcription start site and help form the transcription initiation complex. Other transcription factors bind to regulatory sequences, such as enhancer sequences, and can either stimulate or repress transcription of the related gene.
Can transcription factors be repressors and activators?
According to the conventional wisdom, transcription factors are typically classified as “activators” or “repressors”. Activators recruit coactivators, resulting in gene activation, while repressors recruit corepressors, leading to transcriptional repression.
Do transcription factors inhibit gene expression?
Transcription factors are proteins that bind to the upstream regulatory elements of genes in the promoter and enhancer regions of DNA and stimulate or inhibit gene expression and protein synthesis. They play critical roles in embryogenesis and development.
Can transcription factors inhibit transcription?
Abstract. Although the majority of the transcription factors that were initially characterized had a stimulatory effect on gene expression, it is now clear that transcription factors that inhibit gene transcription are at least as important in regulating a wide variety of processes, including development.
What is the difference between activator and repressor?
An activator acts as a catalyst in the transcription process to produce more mRNA, while the repressor represses RNA polymerase to transcribe the associated genes within an operon.
Are transcription factors activators?