Eukaryote mRNA decay

Nearly all mRNAs subjected to poly (A) tail shortening. When tail < 30 A’s residues in length, Poly (A) binding protein is lost and 3’ end no longer associates with cap. This leads to decapping followed by degradation. Cleavage at the endonuclease cleavage site in the 3’ UTR results in decapping followed by degradation.