The Pros And Cons Of Transcription Factors

Key points:

• Transcription factors are proteins that help turn specific genes "on" or "off" by binding to nearby DNA.

• Transcription factors that are activators boost a gene's transcription. Repressors decrease transcription.

• Groups of transcription factor binding sites called enhancers and silencers can turn a gene on/off in specific parts of the body.

• Transcription factors allow cells to perform logic operations and combine different sources of information to "decide" whether to express a gene.

Introduction

Do you have any transcription factors in your body? I sure hope the answer is yes, because otherwise, you're going to have a hard time keeping your cells running!

Transcription factors are proteins that regulate the transcription

This would lead to very little protein getting made.

Various factors control how much a gene is transcribed. For instance, how tightly the DNA of the gene is wound around its supporting proteins to form chromatin can affect a gene's availability for transcription.

Proteins called transcription factors, however, play a particularly central role in regulating transcription. These important proteins help determine which genes are active in each cell of your body.

Transcription factors

What has to happen for a gene to be transcribed? The enzyme RNA polymerase, which makes a new RNA molecule from a DNA template, must attach to the DNA of the gene. It attaches at a spot called the promoter.

In bacteria, RNA polymerase attaches right to the DNA of the promoter. You can see how this process works, and how it can be regulated by transcription factors, in the lac operon and trp operon videos.

In humans and other eukaryotes, there is an extra step. RNA polymerase can attach to the promoter only with the help of proteins called basal (general) transcription factors. They are part of the cell's core transcription toolkit, needed for the transcription of any