Which of the following levels of control involves the use of a poly-A tail?

Question

protein activity

translation of mRNA

mRNA processing

Transcriptional control

all the above

Answer 1

-It has nothing to do with protein activity, there's no poly A tail on the proteins.

-Translation of mRNA. The poly A tail is like a time control for the mRNA. mRNA is pretty unstable and degrades rapidly in the cell. The 5' cap and poly A tail help the mRNA's longevity. The longer the tail, usually, the longer the mRNA hangs around and translates more proteins before it is degraded.

-mRNA processing entails the addition of the poly A tail.

-It has nothing to do with transcriptional control. The poly A tail is added after transcription.

Answer 2

Poly-A refers to polyadenylation, which is the addition of the base adenine to the end of a mRNA strand. This, along with the 5' cap at the other end of the mRNA protect the mRNA from exonucleases present in the cytoplasm of the cell.

If it weren't for the poly-A tail, important bases for the production of a protein could be cut away before they make it to the ribosome for translation and the protein would not be complete.