What is the role of an activator during control of gene expression?
What is the role of an activator during control of gene expression?
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. Most activators are DNA-binding proteins that bind to enhancers or promoter-proximal elements.
What is the function of repressors for gene regulation?
A repressor is a protein that turns off the expression of one or more genes. The repressor protein works by binding to the gene’s promoter region, preventing the production of messenger RNA (mRNA).
What role do activators play in gene transcription?
Activator proteins bind to regulatory sites on DNA nearby to promoter regions that act as on/off switches. This binding facilitates RNA polymerase activity and transcription of nearby genes.
How are activators and repressors involved in gene expression?
Both repressors and activators regulate gene expression by binding to specific DNA sites adjacent to the genes they control. In general, activators bind to the promoter site, while repressors bind to operator regions.
Which is the main point of control for regulating gene expression levels?
While the expression of gene products can be regulated at many different steps as the information moves from DNA to RNA to protein, the main point of control is the level of transcription. Inhibiting the transcription of genes that are not currently needed help keep unnecessary intermediates from being synthesized.
Why is gene regulation important?
Gene regulation is an important part of normal development. Genes are turned on and off in different patterns during development to make a brain cell look and act different from a liver cell or a muscle cell, for example. Gene regulation also allows cells to react quickly to changes in their environments.
What factors regulate the expression of certain genes?
Eukaryotic gene expression is regulated during transcription and RNA processing, which take place in the nucleus, and during protein translation, which takes place in the cytoplasm. Further regulation may occur through post-translational modifications of proteins.
What factors regulate gene expression?
Transcription and translation were physically separated into two different cellular compartments. It therefore became possible to control gene expression by regulating transcription in the nucleus, and also by controlling the RNA levels and protein translation present outside the nucleus.
What is positive control of gene expression?
In the case of positive control, the genes are expressed only when an active regulator protein, e.g. an activator, is present. Thus the operon will be turned off when the positive regulatory protein is absent or inactivated.
