Question

you notice that a particular eukaryotic mRNA fails to undergo the process of capping. You, as a scientist come pu with multiple ways to help out this mRNA function. Out of al the methods there was one which was incorrect. Which one out of all your expt would not work...? A) you try to attach a compound to the MRNA that would get it out of the nucleus B) you try to stall the mRNA in the nucelus until the cell machinery can eventually start synthesizing a cap C) you try to increase the dose of the enzyme poly A polymerase D) you try to increase the levels of proteins that inhibit the function of exunucleases

Answer 1

C). This is incorrect

Lets see:---

As we know that mRNA having cap,A poly A chain.

Cap function:-- First of all, it helps to distinguish between mRNA, tRNA, rRNA because only a mRNA has cap and recognised by Ribosome at 5' end.

Poly A tail function:-- it provides stability to the mRNA so that it is not cleved by exonuclease or others helps in transportation of it outside.

Now case is mRNA cap has been failed so:

Options A). Some chemicals can be applied to overcome such problem because cap is 7-methylation of guanin and any compound can be used which bring such modifications at 5' end of mRNA.

Option B). It can be happen that we give some time to this and allow such techniques so that in nucleus mRNA taking some time and it may be happen that capping will get started when eventually machinary starts it work

Options C). This is incorrect because mRNA capping when starts then produces signals to start polyadenylation(Poly A) at 3'end. So No advantage in increment of poly A polymerase. It does not work because capping starts first. Got it

Option D). Yes, exonuclease activity should be inhibited so that mRNA could be saved. So increment in protein level to inhibit function of exonuclease.