mRNA degradation is an important process in eukaryotes, allowing control of protein synthesis.
Deadenylases are a group of enzymes degrading the poly(A) tails at the 3’ UTR. This shortening of the poly(A) tail gives a lifespan to mRNAs, with transcripts having longer poly(A) tails having longer lifespans. Eukaryotic mRNAs typically last between 10 minutes and 9 hours before they are unable to be translated. It is possible to accelerate deadenylation, changing the rate of mRNA decay.
Decapping enzymes (Dcp1, Dcp2) cleave the m7G cap found at the 5’ end of the mRNA. This exposes a 5’ phosphate group, which is then targeted by Xrn1, and endonuclease that then degrades the mRNA.