mTOR activation has been known to affect protein synthesis. To identify molecular signatures in transcriptome that could enhance protein synthesis, RNA-seq and quantitative proteomics studies were conducted using WT and TSC1 null MEFs. In this study, we found that the activation of mTOR leads to genome-wide 3'UTR shortening in mRNAs by alternative polyadenylation and activates ubiquitin-mediated proteolysis