Q17.3-3CC - Campbell Biology

Question

What would be the effect of treating cells with an agent that removed the cap from mRNAs?

Step-by-Step Solution

Answer

The cap acts as a protection for the mRNA. The removal of the cap from the mRNA can make the mRNA vulnerable to damage. It affects protein formation.

Step 1: Definition of mRNA

mRNA is the messenger RNA produced from the process of transcription. It is the process that converts the DNA into mRNA mediated by the enzyme called RNA polymerase. The transcription factors are the factors that assist the RNA polymerase in identifying the promoter sequences. 

Step 2: Meaning of capping

Capping is the mechanism that adds protection to the ends of the 5’ end of the mRNA. The enzymes involved in capping are RNA triphosphatase, guanylyltransferase (or CE), and methyltransferase. Capping occurs by the process of methylation.

Step 3: Effect of treating the cells with an agent

In the given condition, the cells are treated with agents that remove the capping present in the mRNA. It is an essential post-transcriptional modification step. 

Capping protects the mRNA from the immune attack toward the self cells. It is the signal for the initiation of RNA translation. It also protects the RNA from disintegration.

The removal of capping exposes the RNA to damage, which prevents the process of translation. As a result, protein formation does not happen.

Hence, removing the cap from mRNA leads to mRNA destruction and stops protein formation.