What Is the Degradation of mRNA?

••• poba/E+/GettyImages

Messenger RNA (mRNA), transcribed from a gene on a DNA template, carries information that encodes the directions for protein synthesis by ribosomes. Each of the 25,000 to 30,000 genes in the human genome are present in most of your body cells, but each cell expresses only a small fraction of them. Messenger RNA degradation is one of the methods used by cells to regulate which genes are expressed and when.

Levels of Gene Regulation

Gene expression can be regulated at several levels in a cell. Differential gene transcription regulates which genes are allowed to be transcribed into RNA while selective nuclear RNA processing regulates which transcribed RNA can enter the cytoplasm and become messenger RNA. Genes can be regulated any time before, after or during the processes of translation and transcription.

Transcription

Transcription is the synthesis of messenger RNA from a DNA template. The mRNA created from the process of transcription can leave the nucleus and enter the cytoplasm where it is transcribed by ribosomes to create protein products.

mRNA Degradation

Different messenger RNA are translated at different rates by the cell. Each mRNA differs in the rate at which they are translated into protein and in the stability of the mRNA molecule. The longer-lasting an mRNA molecule is, the more protein products that can be transcribed from the mRNA sequence.

mRNA Half-life

Most bacterial mRNA have a half-life of only a few minutes with bacterial mRNA half-lives varying from less than 1 minute up to 20 minutes. The average half-life of human mRNA is 10 hours with human mRNA half-lives varying between 30 minutes and 24 hours.

Increasing Stability

While cells degrade messenger RNA to regulate the amount of proteins that can be translated from each mRNA molecule, they also modify mRNA molecules in a way that increases the stability of the molecule and increases the protein output under specific conditions and at certain times. The addition of a polyA tail to the 3' end of an mRNA molecule increases the stability of the mRNA molecule. The longer the polyA tail, the more stable the molecule and the more protein that can be translated.

Related Articles

How Does Phosphorylation Affect Protein Activity?
rRNA: What is It?
Why Are There Many Different Types of tRNA Molecules?
The Three Ways That a Molecule of RNA Is Structurally...
What Is the Importance of Nucleic Acids?
How Does DNA & RNA Differ?
What Are mRNA, rRNA & tRNA?
Why Are There 61 Anticodons?
Human Genome DNA Sequence Types
How Does Phosphorylation Affect Protein Activity?
Difference Between Transcription and DNA Replication
What are the Small Parts of the DNA that Code for a...
What is the Subunit of DNA Called?
List the Kinds of Information That Can Be Found by...
Difference Between Recombinant DNA & Genetic Engineering
What Are the Benefits of Ribosomes?
How Do Scientists Construct Recombinant DNA Molecules?
Five Types of Gene Splicing Mechanism
Importance of Free Ribosomes