You are treating cultured cells with an experimental compound. You find that addition of the compound results in a 2-fold increase in the expression of a specific gene. However, you find that the addition of the test compound causes a 10-fold increase in the level of the protein derived from the gene. The major effect of this experimental compound is most likely to be a decrease in which of the following?
A) degradation of mRNA by nucleases
B) rate of mRNA translation
C) rate of ribosomes binding to mRNA
D) RNA polymerase II activity
E) splicing of nascent RNA transcripts

Question

Quizplus · Accepted Answer

The compound likely decreases the degradation of mRNA by nucleases, leading to more mRNA available for translation, which results in a greater increase in protein levels compared to mRNA levels.  The disconnect between the level of gene expression, which results in mRNA increases and the level of protein increases from the resultant mRNAs can be accounted for by numerous consequences. However, in this case the most likely cause of the dramatically elevated level of protein from a slight elevation in mRNA levels is increased mRNA stability. The more stable mRNA can be engaged by the translational machinery more often resulting in more protein being made. Therefore, the test compound is most likely inhibiting the degradation of mRNAs by ribonucleases.

You Are Treating Cultured Cells with an Experimental Compound